Comprehensive Review of the Scientific Literature Including a Summary of Key Findings

Attachment 1: Comprehensive review of the scientific literature including a summary of key findings.

REDUCING HARM TO OLDER PERSONS IN VICTORIA FROM EXTREME HOT WEATHER

Literature Review

Executive Summary

Judith McInnes, Joseph Ibrahim, Margaret Loughnan

April 2008

3 Executive summary Introduction Periods of extremely hot weather, also referred to as ‘heatwaves’, are known to be associated with marked, short-term increases in mortality in exposed populations. Climatologists have concluded that that as a consequence of global warming, it is very likely that heatwaves will become more intense and more frequent in the future. The number of people at increased risk from the adverse health effects of heatwaves in Australia is expected to increase in conjunction with ageing of the population and increased urbanisation.

Strategies must be developed to promote adaptation to the consequences of climate change in order to minimise its potential negative health impacts, including the development of effective responses to heatwaves. The development of public health strategies to reduce the harm to older persons from extreme hot weather requires an understanding of the relationship between hot weather and human health, of factors influencing the vulnerability of populations to heat-related morbidity and mortality, and the identification of effective public health interventions.

For the purpose of informing the development of effective harm minimisation policies and strategies for use in Victoria, the Environmental Health Unit of the Department of Human Services (Victoria) has commissioned a study by Monash University to examine the current knowledge of the health effects of heatwaves, the national and international experience of successful heatwave risk reduction strategies, and the awareness and practice of Victorian health professionals and carers regarding heatwaves and the elderly. The following literature review is one component of this study. The purpose of the review was to review the local and international experience, knowledge and practices regarding extreme hot weather and the elderly. The key questions that have guided the review are:

1. How should an episode of ‘extreme hot weather’ be defined? 2. Are heatwaves expected to occur more frequently in the future? 3. What has been the health burden from heatwaves in Australia and internationally? 4. What factors influence the risk of death and illness occurring in association with an episode of extreme hot weather? 5. Which population groups are at most risk of harm from extreme hot weather? 6. Why are the elderly particularly vulnerable to extreme hot weather? 7. What strategies have been adopted to reduce harm to the elderly due to extreme hot weather? 8. How effective are these harm minimisation strategies?

4 Purpose of study:  To review the local and international experience, knowledge and practices regarding the health effects of heatwaves, and heatwave risk reduction strategies, in order to inform the development of effective harm minimisation policies and strategies for use in Victoria. Method  A detailed review of the literature was made, utilising a broad search strategy, to identify the material required to address eight key questions devised to guide the review.  Information was sought from peer-reviewed journals, Government and International agency reports and publications, conference proceedings, and relevant text-books, through searches of library databases, bibliographies of retrieved articles, contents of relevant peer-reviewed journals, and search of internet web sites.

 Key words used for database searched included: included: heatwaves, heat waves, heat-related mortality, heat, temperature, ambient temperature, weather, mortality, morbidity, elderly, aged, frail aged, emergency, emergency response plan, heatwave response plan, time-series analysis, excess deaths, heatstroke, public health, climate change, global warming.

 Additional information was sought directly from Government Department, Universities and other professional organisations in Australia and internationally, by email and telephone.

 Inclusion criteria applied to retrieved literature were: English language articles; peer-reviewed journal articles, 1985-2008; publications from Australian and International agencies, 2000- 2008; analyses of the health consequences of specific heatwave events; scientific articles and publications discussing models and projections of climate change, particularly related to temperature; relationship between high ambient temperature and health; the influence of ageing on thermoregulation; reviews of the health impacts of climate change; reviews of the health impacts of heatwaves.  Exclusion criteria applied to retrieved literature were: Non-English language; articles focusing on the relationship between low ambient temperature and mortality or health effects of hot weather on children.  Retrieved literature was used to identify what is known and practiced, gaps in knowledge, and areas of controversy relevant to the study objectives.

Results

1. Definitions and Background Information Elderly:  For the purpose of this literature review, the term ‘elderly’ is used to refer to people who are aged 65 years or over.

Extreme hot weather: 5  In this review, an episode of ‘extreme hot weather’ is referred to as a ‘heatwave’. There is no standard definition of the term ‘heatwave’, with a variety of definitions used in the literature, each describing an event threshold and duration that are observed to be associated with increased morbidity and mortality of the population studied. See below for more details.

Heat-related illness and death:  This term refers to a spectrum of disorders caused by exposure to excessive environmental heat, including sunburn and fatigue, heat rash, heat cramps, heat syncope, heat exhaustion, and heat stroke. The most serious of these are heat exhaustion and heat stroke, which can lead to death.

 A number of definitions of ‘heat-related death’ are found in the literature. Many deaths occurring during heatwaves are not clinically apparent as being due to heat, so it is likely that the number of heat-related deaths is underestimated.

Heat-associated illness and death:  Not all deaths and illnesses occurring in association with heatwaves are recognised as part of the spectrum of heat-related spectrum of disorders, but rather are due to an exacerbation of pre- existing illness. Therefore, the terms ‘heat-associated illness’ and ‘heat-associated death’ are used to refer to the full spectrum of the health burden attributable to heatwaves.

Excess deaths:  This is an expression of the number of deaths occurring over and above what would be expected for a particular population during a given time period. This measure is used when assessing the health burden of heatwaves to avoid the problem of deciding which deaths are ‘heat-related’.

The human response to hot weather:

 Physiological responses that help to keep body temperature normal in hot weather are sweating and increased blood flow to the skin. Behavioral responses that help to do this are reducing activity, seeking cool environments, wearing loose, light clothing, and using cooling devices.  Maintenance of homeostasis during hot weather requires adequate functional capacity of numerous body systems including the nervous, cardiovascular, renal, musculoskeletal and hormonal systems, as well as behavioral responses supported by access to appropriate resources and cool environments.

2. How should an episode of extreme hot weather be defined?

 An episode of extreme weather, or heatwave, is difficult to define since the response to extreme hot weather varies between populations and within populations, and over time, with vulnerability influenced by opportunity for acclimatisation as well as population and heatwave characteristics.  The basic components of a heatwave definition are event threshold and duration that are observed to be associated with increased morbidity and mortality of the population in question. 6  Thresholds are values of meteorological conditions that reflect the vulnerability of the population under study, and can be temperatures or derived heat indexes  A general definition of a heatwave is “a prolonged period of excessive heat”.  Lack of a universal definition makes comparison of heatwave event and analysis of frequency of heatwave events difficult.

3. Are heatwaves expected to occur more frequently in the future?

 Climate scientists have concluded that global warming is undoubtedly occurring.  It is predicted that extremes of temperature and heat waves will become more frequent, more intense and longer lasting in the future.  The projected rise in global temperature is predicted to result in an increase in heat-related deaths in Australian cities.

4. What has been the health burden from heatwaves in Australia and internationally?

4.1 Mortality and heatwaves  Specific heatwave events in the Northern hemisphere have been associated with marked short- term increases in mortality, with reported excess mortality ranging from 4% to 142%. It is estimated that in 2003, up to 70,000 additional deaths occurred over the summer months in Western Europe as a consequence of severe heatwaves.  Lag times of just a few days have been observed between the onset of a heatwave and the rise in mortality, suggesting that people succumb quickly to the effects of extreme heat.  Not all, and sometimes very few of the excess deaths occurring in heatwaves are reported to be directly attributable to the effects of excessive heat, but rather are due to exacerbation of pre- existing illnesses, particularly cardiovascular and respiratory diseases, and diseases of the nervous system.  There is evidence that only a small proportion of excess deaths occurring in heatwaves represent short-term mortality displacement.  A disproportionately large fraction of excess deaths occurred in hospitals and nursing homes during the 2003 heatwave in Europe, when air-conditioning was uncommon in these facilities.  Mortality associated with heatwaves has been reported to be greatest in city areas, in conjunction with observed high night-time minimum temperatures, high levels of air pollution, and poor housing conditions.  Air pollution was found to have contributed to a proportion of the excess deaths occurring during heatwaves in England and Wales, though the nature of the relationship between air pollution and high temperature requires further investigation.

4.2 Morbidity and heatwaves  Few studies have investigated the effects of extreme hot weather on population morbidity 7  Hospital admissions have been observed to increase during heatwaves; however studies have revealed discrepancies between the impact of heatwaves on morbidity and mortality, in terms of magnitude, cause, and age group.  Reports of a lesser impact of heatwaves on hospital admissions than on mortality may indicate that people die quickly during heatwaves before they are able to reach hospital or be noticed by others.  An analysis of underlying cause of admission, has demonstrated that individuals with pre- existing cardiovascular disease, diabetes, renal disease, or nervous system disorders are at most risk of hospitalization for treatment of heatstroke, heat exhaustion and acute renal failure.  Studies of patients admitted to hospitals during heatwaves for treatment of heatstroke have shown this illness to be associated with a poor short and long-term outcome.

4.3 The Australian context  While the health burden of heatwaves has been less extensively documented for Australia than for the Northern hemisphere, it has been estimated that more than 4,000 deaths have occurred over the part 100 years as a consequence of heatwaves, twice the number caused by cyclones or floods over the same period of time.

 It is predicted that increased global temperatures associated with global climate change will result in an increase in heat-associated deaths in Australian cities.  A threshold maximum temperature above which mortality is observed to increase in eastern Australian cities is approximately 28-30°C.  In Melbourne, a relationship has been observed between morbidity, mortality and temperature, with population vulnerability being influenced by age, socioeconomic status, and location of residence with regard to the urban heat island.  An average temperature of 30°C has been has been shown to result in a 4-10% increase in admissions for myocardial infarction to Melbourne hospitals.  In Melbourne, thresholds of daily average temperature greater than 30°C, and daily minimum temperature greater than 24°C, have been found to be associated with increased mortality rates for those aged 64 years or older.  The results of Australian studies are consistent with those from the Northern hemisphere, except that threshold temperatures above which mortality increases in eastern Australia are relatively consistent irrespective of latitude and daily or seasonal temperature ranges.

5. What factors influence the risk of death and illness occurring in association with an episode of extreme hot weather?  Factors that influence the risk of illness and death during heatwaves include characteristics of the heatwave event itself, as well as characteristics of the exposed individuals, and the environment in which they live. 8  Episodes of hot weather posing the greatest threat to exposed populations are those characterised by consecutive days of maximum day-time temperatures much hotter than usual for that location, with hot nights, and occurring early in the summer period.  Characteristics of individuals found to be most strongly associated with an increased susceptibility to poor health outcomes during heatwaves are being : . aged 65 years or older, . socially isolated, . dependant on others for care particularly if confined to bed, . poor, . homeless, . and having a pre-existing illness.  Pre-existing illnesses most strongly associated with an increased risk of death during heatwaves are cardiovascular disease, psychiatric illness, cognitive impairment and other neurological disorders, respiratory disease, cancer, diabetes and obesity. These illnesses, and medications used in their treatment, may increase vulnerability through compromising thermoregulation, mobility, awareness of a hot environment, and the ability to adopt protective behaviors.  Characteristics of environments in which people live that have been found to increase the risk of death associated with heatwaves include living in geographical locations with variable weather patterns, living in cities, and living in housing that lacks insulation, and has bedrooms located directly under the roof.  Having a working air-conditioner, visiting cooler environments, and participating in social activities have been identified as factors most strongly protective against death during heatwaves.  Fans are not considered effective when temperature and humidity are high, and may be harmful if used in enclosed, hot environments.

6. Which population groups are at the most risk of harm from extreme hot weather?

 Vulnerability to extreme hot weather is increased in individuals with compromised physiological responses to excessive heat, those who have reduced ability to modify their behavior in order to care for themselves or reduce their exposure to hot weather conditions, and those who have limited access to resources such as air-conditioners, shelter, transportation, cool spaces, and drinking water.  Population groups most vulnerable to harm during heatwaves are the elderly, the very young, those taking certain prescribed medications, people with chronic illnesses, people with psychiatric illnesses, the homeless, people who are socially isolated, those who are economically deprived, and those who abuse alcohol and/or illicit drugs. 9 7. Why are the elderly particularly vulnerable to extreme hot weather?  A combination of factors diminish the elderly individual’s capacity to maintain a normal body temperature and adequate hydration during extremely hot weather, including the effects of ageing, chronic illness and disability, prescribed medication, and social factors.

 Age-related changes can diminish the effectiveness of thermoregulatory responses, as well as thirst and renal mechanisms for regulation of body fluid balance.  Chronic illnesses known to be associated with an increased risk of death during heatwaves are more prevalent in the elderly. These illnesses, and medications used in their treatment, can increase vulnerability to hot weather through compromising thermoregulation, mobility, awareness of a hot environment, or the ability to adopt protective behaviors.  A number of medications used for management of illness in the elderly can contribute to adverse health outcomes during heatwaves through promoting fluid loss, interfering with thermoregulatory mechanisms, or causing sedation.  A large proportion of elderly people live alone. Social isolation is a risk factor for death during heatwaves, and can occur as a result of loss of partner, poor health, mental illness, being a carer, living in an isolated rural area, not speaking English as a first language, being fearful of assault, and lacking access to suitable public transport.

8. What strategies have been adopted to reduce harm to the elderly due to extreme hot weather?  Harm minimisation strategies include public education to promote modification of individual behavior using health education programs or written behavior guidelines, the more comprehensive heatwave response plans that use meteorological forecasts to initiate public health interventions, and long-term prevention strategies such as building design and urban planning.

8.1 Public education  A number of Government Health Departments and health agencies provide health education programs and written guidelines for personal strategies to minimise harm from heatwaves.  Heat health education programs mentioned in the literature include those for the general public, for vulnerable groups, and for health care providers, carers and volunteers.  Guidelines for personal strategies to assist members of the public minimise the health effects of extreme heat for themselves and those around them can be found on web-sites, in leaflet form or in media releases.  It is unlikely that passive dissemination of prevention guidelines will be effective if unaccompanied by active outreach to vulnerable groups, since these groups maybe unable to access or act upon this type of information. 10 8.2 Heatwave response plans  Heatwave response plans provide details of actions that government and non-government agencies can take in the event of a heatwave being forecast, in order to reduce heat-associated death and illness.  A number of cities have developed Heatwave Response Plans that include warning and public health intervention components.  Heatwave warning systems have been developed for cities using meteorological data to predict the likelihood of predetermined thresholds of heat-stress indicators being exceeded. These thresholds are based on an understanding of the relationship between weather and human health for the population and locality in question.  Public health interventions utilised by Heatwave Response Plans around the world have a number of common elements, these having been based on an understanding of the sudden onset of heat-related illness, of risk factors for illness and death during heatwaves, and of the characteristics of vulnerable groups in populations.  A number of commentators have made recommendations regarding important factors to include in the process of heatwave response planning.  Only two Australian States have any type of operational Heatwave Response Plan: that in Queensland which covers the area of South East Queensland including Brisbane, and a pilot program operating for the Central Coast Region of NSW. Both responses have a two-tiered alert system but differ considerably in their scope and details.  Research and pilot projects are currently underway in Victoria for the purpose of informing the development of a Statewide Heatwave Response Plan..

 Essential components of heatwave response planning identified in the literature are:

o Identification of a principle coordinating agency and other participating organisations. Preparations before the heatwave Identification and forecasting of a dangerous heatwave event. Assessment of the risk posed by the heatwave to the exposed population A consistent, standardised warning system that is activated and deactivated according weather conditions. The use of communication systems and public education programs. Public health interventions that target high-risk groups. Ongoing evaluation of plan effectiveness. Plan revision  Main types of public interventions reportedly used in heatwave response plans are: 11 o Provision of information to individuals and groups, regarding heatwave warnings and avoidance of heat associated illness, through the media, internet, leaflets, emails, telephone calls, direct contact. o A telephone service that can provide information, advice and a referral service. o Designated air-conditioned buildings are used as cooling shelters for the general public. o Provision of transportation to cooling centers. o Extension of the hours of operation of places where people can seek relief from the heat such as air-conditioned community centers and swimming pools. o Ensuring extra emergency services and hospital staff are available. o Suspension of utility shut-offs due to non-payment during heatwave alert period. o Outreach activities, including home visits to registered at-risk individuals, checking of isolated neighbours using ‘buddy’ systems, and actively seeking out homeless individuals.

o Provision of sources of free drinking water.

8.3 Long-term harm minimisation strategies  Long term harm minimisation strategies include improved building design, the reduction of urban heat islands, reduction of green house gas production, and improved fitness of the population.  Strategies that have been reported for reducing the urban heat island effect include applying light reflecting roof paint, improving house insulation, planting trees, using light coloured building materials, installing roof-top gardens, and creating ventilation corridors.

8.4 Programs that indirectly address risk factors for heat associated death  Programs that address the issues of social isolation, poor housing conditions and economic deprivation of the elderly may contribute to minimising harm during heatwaves, without being specifically focused on this issue.  Examples of such programs include the Red Cross ‘TeleCross Program’, and the Housing NSW Care Call program instituted by the New South Wales Department of Housing.

9. How effective are these harm minimisation strategies?

 There has been limited formal evaluation of the effectiveness of heatwave response plans or of individual intervention measures.  Four studies of successive heatwaves in the same location have reported a reduced heath impact of heatwaves subsequent to the institution of public health preparedness and response programs. However, while these measures may have contributed to the observed reductions in mortality, population vulnerability is also influenced by a number of other factors. 12  Surveys of public awareness and response to heatwave warnings have found that while most respondents were aware when heat warnings were issued, less than half modified their behavior as recommended. Perceptions of risk strongly influenced the likelihood of individuals following heat protection advice.  Reports of health agencies have provided some insight into the effectiveness of individual intervention measures, including peak access times for telephone help-lines, access to participating agencies, distribution of air-conditioners, utilization of cooling shelters, drop-in centres for homeless individuals, use of shopping centres as cool spaces, and closing of schools when temperatures reach threshold levels.  It has been recommended that standardised evaluation guidelines be developed to facilitate comparable evaluation of the increasing number of heatwave plans in operation.

Conclusions  The people most likely to die or be admitted to hospital during extreme hot weather are the elderly. Those who die are more likely to live alone, to be socially isolated, economically disadvantaged, and to have co-existing debilitating diseases, reflecting a complex interaction of physiological, social, behavioral and pathological factors that combine to increase the vulnerability this population group to heat associated morbidity and mortality.

 Deaths occurring during heatwaves are not always due to hyperthermia but are often due to an exacerbation of underlying cardiovascular, respiratory or other disease. Furthermore, only a small proportion of these deaths appear to be due to the forward advancement of deaths expected to occur in the near future.

 Heatwaves having the greatest impact on health are those occurring early in the summer season, particularly in cities and locations where populations have had little experience of sustained periods of hot weather; several days of extreme temperatures, with high night-time temperatures are the most lethal.

 The death toll from a heatwave appears early in the event, with many people succumbing quickly before they are able to reach medical help, or be noticed by others.

 There is evidence that having a working air conditioner in the home, spending time in cooler locations during a heatwave, and participating in social activities reduces the risk of death during a heatwave.

These findings have implications for public health policy, and for the development of a Statewide Health Response Plan. In particular:

 The rapid onset of heat-associated illness underlies need for planning before heatwave season, early prevention strategies, and prior identification of the most vulnerable groups.  The health impact of high night-time temperatures suggests that the availability of public health measures during the night as well as the daytime, such as a telephone help and advisory line, out-reach activities, and access to cool environments, are important.  The relationship between chronic disease and risk of death during heatwaves highlights the importance of prevention and management of these conditions.  Long-term measures are also needed to address the urban heat island effect, particularly to enhance cooling of cities during the night.

A number of research gaps have been identified in the literature. These include:

 Limited evaluation of the effectiveness of heat wave response plans and of individual response interventions, despite the large number of heatwave response plans described.  A lack of evidence to explain more precise mechanisms connecting risk factors with outcomes, such as the relationship between social isolation, or psychiatric illness and morbidity and mortality during heatwaves.  There is little information regarding minimum time to be spent in a cooler environment for protection from death during a heatwave, or the appropriate use of some interventions, including the use of fans, drinking extra water, taking extra showers and baths, all of which could be hazardous in some situations for some people.  Information regarding the effects of extreme heat on the morbidity of populations is also limited.  Most evidence of the relationship between extreme heat and human health is derived from studies of populations living in Northern hemisphere cities. Few studies are available regarding Australian populations.

REDUCING HARM TO OLDER PERSONS IN VICTORIA FROM EXTREME HOT WEATHER

Literature Review

Judith McInnes, Joseph Ibrahim, Margaret Loughnan

April 2008

15 Table of Contents

Executive summary...... 3

Introduction...... 3

Purpose of study:...... 4

Method ...... 4

Results ...... 4 1. Definitions and Background Information ...... 4 2. How should an episode of extreme hot weather be defined?...... 5 3. Are heatwaves expected to occur more frequently in the future?...... 6 4. What has been the health burden from heatwaves in Australia and internationally? ...... 6 4.1 Mortality and heatwaves...... 6 4.2 Morbidity and heatwaves...... 6 4.3 The Australian context ...... 7 5. What factors influence the risk of death and illness occurring in association with an episode of extreme hot weather? ...... 7 6. Which population groups are at the most risk of harm from extreme hot weather?...... 8 7. Why are the elderly particularly vulnerable to extreme hot weather? ...... 9 8. What strategies have been adopted to reduce harm to the elderly due to extreme hot weather?...... 9 8.1 Public education ...... 9 8.2 Heatwave response plans...... 10 8.3 Long-term harm minimisation strategies...... 11 8.4 Programs that indirectly address risk factors for heat associated death ...... 11 9. How effective are these harm minimisation strategies?...... 11

Conclusions...... 12

Table of Contents ...... 15

1. Introduction...... 19 Box 1. Key Questions ...... 20

2. Method ...... 21 2.1 Peer reviewed publications, database search & keywords...... 21 2.2 Grey Literature...... 21 2.3 Inclusion & exclusion criteria...... 22

3. Results ...... 23 SECTION A: Data Retrieved and Definitions...... 24 3.1 Data Retrieved...... 24 3.2 Definition of Terms...... 25 3.2.1 Elderly...... 25 3.2.2 Extreme hot weather ...... 25 16 3.2.3 Heat-related illness and death ...... 25 3.2.4 Heat-associated illness and death...... 26 3.2.5 Excess deaths ...... 26 SECTION B: Background Information ...... 27 3.3 Human responses to extreme hot weather...... 27 3.3.1 Thermoregulation...... 27 3.3.2 Heat-related illness...... 28 3.3.2.1 Heat Exhaustion ...... 28 3.3.2.2 Heatstroke ...... 29 Box 2. Main points - The human response to extreme hot weather...... 29 3.4 How should deaths attributed to heat be defined and quantified? ...... 30 3.4.1 Defining heat-related death...... 30 3.4.2 Defining & calculating excess deaths ...... 30 Box 3. Main points - The definition and quantification of deaths attributed to extreme hot weather...... 31 SECTION C: Extreme Hot Weather...... 32 3.5 Definition of ‘extreme hot weather’...... 32 Box 4. Main points - Definition of ‘extreme hot weather’ ...... 33 3.6 The likely frequency and impact of heatwaves in the future...... 34 Box 5. Main points - The likely frequency and impact of heatwaves in the future...... 35 SECTION D: Health Burden of Extreme Hot Weather...... 36 3.7 Mortality...... 36 3.7.1 Magnitude of impact of heatwaves on mortality...... 38 3.7.2 Age, sex and socioeconomic status of exposed population ...... 38 3.7.3 Lag times...... 39 3.7.4 Cause of death...... 39 3.7.5 Place of death...... 40 3.7.6 Forward displacement of mortality...... 40 3.7.7 Temperature thresholds for increased mortality ...... 41 3.7.8 Mortality and temperature variables ...... 42 3.7.9 Mortality and acclimatisation to hot weather...... 42 3.7.10 Influence of air pollution...... 43 3.7.11 Modeling heat events ...... 44 Box 6. Main points - Mortality and heatwaves...... 46 3.8 Morbidity ...... 47 3.8.1 Hospital admissions ...... 47 3.8.2 Ambulance transportation...... 49 3.8.3 Heatstroke ...... 49 Box 7. Main points - Morbidity and heatwaves...... 51 3.9 The Australian Context ...... 51 Box 8. Main points -The Australian Context...... 53 SECTION E: Risk factors for heatwave-associated illness and death...... 54 3.10 Factors that increase the risk of death and illness associated with heatwaves...... 54 3.10.1. Characteristics of heatwave event...... 55 3.10.2 Characteristics of exposed individuals...... 55 3.10.2.1 Age...... 55 3.10.2.2 Social isolation...... 56 3.10.2.3 Being dependent on others for care...... 56 3.10.2.4 Pre-existing illness ...... 56 17 3.10.2.5 Lower socioeconomic status ...... 58 3.10.2.6 Homelessness...... 58 3.10.3 Characteristics of environments in which people live ...... 58 3.10.3.1 Geographic location ...... 58 3.10.3.2 Cities ...... 59 3.10.3.3 Housing ...... 59 Box 9: Main points - Factors that increase risk of death and illness associated with heatwaves ...... 60 3.11 Factors that decrease the risk of death and illness associated with heatwaves...... 61 3.11.1 Fans ...... 61 Box 10: Main points - Factors that decrease risk of illness and death associated with heatwaves...... 62 SECTION F: Vulnerable groups...... 63 3.12 Vulnerability of the elderly to extreme hot weather...... 64 3.12.1 Effects of ageing ...... 64 3.12.1.1 Thermoregulation...... 64 3.12.1.2 Thirst mechanism...... 64 3.12.1.3 Renal function...... 65 3.12.1.4 Reduced fitness ...... 65 3.12.2 Chronic illness and disability...... 65 3.12.3 Prescribed medications ...... 66 3.12.4 Social factors...... 66 Box 11: Main points - Vulnerability of the elderly to extreme hot weather...... 67 SECTION G: Harm Minimisation Strategies ...... 68 3.13 Public education...... 68 Box 12: Main points - Public education...... 70 3.14 Heatwave Response Plans...... 71 3.14.1 Effective heatwave response planning...... 72 Box 13: Essential components of heatwave response planning identified in literature...... 72 3.14.2 Public health interventions used in heatwave response plans...... 74 Box 14: Main types of public health interventions used in Heatwave Response Plans...... 75 Box 15: Notable aspects of a selection of heatwave response plans...... 76 3.14.3 Heatwave Response Plans in Australia...... 78 3.14.3.1 Queensland...... 78 3.15.4.2 New South Wales...... 79 Box 16: Main points - Heatwave Response Plans ...... 80 3.15 Long-term strategies for minimising harm from heatwaves...... 80 3.15.1 Building design ...... 81 3.15.2 Reduction of urban heat islands...... 81 3.15.3 Other strategies ...... 82 Box 17: Main points - Long-term harm minimisation strategies...... 82 3.16 Programs that indirectly address risk factors for heat associated death and illness...... 83 Box 18: Main points - Strategies that indirectly address risk factors for harm during heatwaves...... 84 3.17 Evaluation of harm minimisation strategies...... 84 Box 19: Main points - Evaluation of strategies to minimise harm during heatwaves...... 89

4. Summary & Conclusion ...... 90 18 Box 20: Summary of responses to key questions guiding the literature review...... 90

5. Glossary ...... 95

6. Appendix: Tables 1 - 21...... 97 Table 1: Definitions of 'heat-related death' ...... 97 Table 2: Definitions of the term ‘Heatwave’ ...... 98 Table 3: Examples of different methods used to estimate 'excess deaths'...... 99 Table 4: Descriptive studies of mortality associated with specific heatwave events...... 100 Table 5: Time-Series Analyses of Mortality-Temperature Relationship...... 102 Table 6: Studies of morbidity associated with heatwave events...... 106 Table 7: Studies of risk factors for heatwave associated illness and death...... 109 Table 8: Factors found to increase the risk of heat-related death...... 111 Table 8 cont. Factors found to increase the risk of heat-related death...... 112 Table 9: Factors found to decrease the risk of heat-related death...... 113 Table10: Examples of guidelines for personal strategies during heatwaves...... 114 Table11: Heatwave Response Plans - Public Health Interventions: Toronto ...... 115 Table12: Heatwave Response Plans - Public Health Interventions: Philadelphia...... 117 Table 13: Heatwave Response Plans - Public Health Interventions: Chicago...... 118 Table14: Heatwave Response Plans - Public Health Interventions: Rome ...... 119 Table15: Heatwave Response Plans - Public Health Interventions: Catalonia, Spain...... 120 Table16: Heatwave Response Plans - Public Health Interventions: United Kingdom...... 122 Table 17: Heatwave Response Plans - Public Health Interventions: Shanghai ...... 124 Table 18: Heatwave Response Plans - Public Health Interventions: Dayton ...... 125 Table 19: Heatwave Response Plans - Public Health Interventions: Milwaukee...... 126 Table 20: Heatwave Response Plans in Australia and New Zealand...... 127 Table 21: Comparison of Heatwave Response Plans in Queensland and NSW...... 128

7. Bibliography ...... 129

1. Introduction Periods of extremely hot weather, also referred to as ‘heatwaves’, are known to be associated with marked, short-term increases in mortality in exposed populations (1). In 2003, a heatwave in Europe led to more than 30,000 excess deaths over a three week period, with those particularly effected being the elderly (2). In Australia, heatwaves are reported to have caused more deaths over the past 200 years than any other natural hazard except for disease (3). While observations of increased mortality associated with heatwaves have been reported in numerous countries for many years (4, 5), predictions of the likely consequences of global warming have highlighted the significance of heatwaves as a public health concern in the future. Climatologists have concluded that not only is global warming undoubtedly occurring, but that it is very likely that heatwaves will become more intense and more frequent in the future (6, 7). Furthermore, the number of people at increased risk from the adverse health effects of heatwaves in Australia is expected to increase in conjunction with ageing of the population and increased urbanisation (8).

While mitigation of factors contributing to global warming is essential if severely damaging disturbances to the earth’s climate are to be avoided, even reducing green house gas emissions to the year 2000 levels immediately would not stabilize global warming for a number of decades (9).

Therefore, strategies must be developed to promote adaptation to the consequences of climate change in order to minimise its potential negative health impacts. One important component of adaptation to climate change is the development of effective responses to heatwaves.

The development of public health strategies to reduce the harm to older persons from extreme hot weather requires an understanding of the relationship between hot weather and human health, of factors influencing the vulnerability of populations to heat-related morbidity and mortality, and the identification of effective public health interventions. 20 For the purpose of informing the development of effective harm minimisation policies and strategies for use in Victoria, the Environmental Health Unit of the Department of Human Services (Victoria) has commissioned a study by Monash University to examine the current knowledge of the health effects of heatwaves, the national and international experience of successful heatwave risk reduction strategies, and the awareness and practice of Victorian health professionals and carers regarding heatwaves and the elderly. The project has three components: a review of the literature, a stakeholder consultation, and a survey of health professionals and carers. The purpose of the following literature review, which is one component of this study, is to review the local and international experience, knowledge and practices regarding extreme hot weather and the elderly. The key questions that have guided the review are provided in Box 1:

Box 1. Key Questions

9. How should an episode of ‘extreme hot weather’ be defined? 10. Are heatwaves expected to occur more frequently in the future? 11. What has been the health burden from heatwaves in Australia and internationally? 12. What factors influence the risk of death and illness occurring in association with an episode of extreme hot weather? 13. Which population groups are at most risk of harm from extreme hot weather? 14. Why are the elderly particularly vulnerable to extreme hot weather? 15. What strategies have been adopted to reduce harm to the elderly due to extreme hot weather? 16. How effective are these harm minimisation strategies?

21 2. Method This detailed review of the literature was made utilising a broad search strategy to identify the material required to address the key issues of the project.

2.1 Peer reviewed publications, database search & keywords Information was sought from peer-reviewed journals by searching an extensive range of databases including MEDLINE, Cochrane library, EMBase, Informit Databases, and CINAHL. The search was conducted for all publications from January 1985 to December 2007.

The keywords used for database searches included: heatwaves, heat waves, heat-related mortality, heat, temperature, ambient temperature, weather, mortality, morbidity, elderly, aged, frail aged, emergency, emergency response plan, heatwave response plan, time-series analysis, excess deaths, heatstroke, public health, climate change, global warming.

The reference list of retrieved articles was followed up for any relevant material. Also, the contents of peer reviewed journals from the subject areas of Public health, Medicine, Science, Environmental science, Gerontology, Meteorology were searched and the bibliographies of retrieved articles checked.

Additional information was sourced directly from individual government departments, universities and other professional organisations contacted by e-mail, telephone or on-site visits. Relevant edited textbooks were also utilised as a resource where necessary.

2.2 Grey Literature Government and other International agency reports were identified through World Wide Web searches.

Specific attention was given to Government Health Departments in Australia, Europe, the United

Kingdom, United States of America and Canada. The project team made direct contact by telephone and email with each of Australia’s State & Territory Health Departments, New Zealand and other international Government Departments for additional information. 22 Internet websites were searched for any relevant information about heatwave statistics, climate change scenarios, morbidity and mortality associated with hot weather, heatwave response plans, public health and heatwaves, evaluation of heatwave response plans, public health interventions developed to minimize adverse health outcomes associated with heatwaves, and public health interventions that address risk factors for mortality associated with heatwaves without this being the prime focus.

2.3 Inclusion & exclusion criteria Criteria were determined for retrieving and reviewing the peer review publications and reports from the grey literature.

The inclusion criteria were: English language articles; peer-reviewed journal articles, 1985-2008; publications from Australian and International agencies, 2000-2008; analyses of the health consequences of specific heatwave events; scientific articles and publications discussing models and projections of climate change, particularly related to temperature; relationship between high ambient temperature and health; the influence of ageing on thermoregulation; reviews of the health impacts of climate change; reviews of the health impacts of heatwaves.

The exclusion criteria were: Non-English language; articles focusing on the relationship between low ambient temperature and mortality or health effects of hot weather on children.

The Project Officer read all the retrieved articles and applied the stated criteria to determine suitability for inclusion in the literature review.

23 3. Results In order to address the key questions guiding this review, literature has been accessed from diverse but overlapping fields of investigation, including meteorological and environmental sciences, studies of the physiological and pathophysiological responses to heat of older persons, surveillance reports of morbidity and mortality occurring during heatwaves, epidemiological studies of associations between hot weather and human health, and public health measures addressing risk factors for adverse health outcomes during hot weather.

Reflecting the wide ranging fields of investigation relevant to this topic, the results of the review are presented in seven main sections, as described below:

Section A: Data Retrieved and Definitions

Section B: Background Information

Section C: Extreme Hot Weather

Section D: Health Burden of Extreme Hot Weather

Section E: Risk Factors for Heatwave-Associated Illness and Death

Section F: Vulnerable Groups

Section G: Harm Minimisation Strategies

Section A and B outline the range of literature retrieved for review, and provide definitions of terms used, as well as background information regarding the human response to extreme hot weather and how this is measured and quantified. The key questions guiding the review are then addressed in Sections C to G, and are provided again for the reader, within the text, as shaded boxes at the commencement of relevant sections.

24 SECTION A: Data Retrieved and Definitions

3.1 Data Retrieved 126 articles were retrieved from the peer-reviewed literature that were considered to be suitable for inclusion in this review. They included 13 review articles, 17 commentaries, and 96 analytical studies.

Also retrieved were 23 reports from international health agencies, 54 documents prepared by

Government Departments and agencies, 2 conference proceedings, 1 doctoral thesis, 13 personal communications with Government personnel, 1 media report, and information from 5 edited textbooks.

The majority of the analytical studies retrieved were ecological studies examining the relationship between exposure to extremely hot weather and human health. This type of study design, in which the unit of analysis is a population rather than an individual, has a number of limitations including lack of ability to accurately measure heat exposure, the variable characteristics of individuals within the population of interest, the possible use of non-representative population samples, and the inability to attribute causality (10, 11). Populations contain individuals that vary with respect to age, health status and housing conditions, all of which could be expected to influence vulnerability to the health effects of hot weather. Mortality and morbidity information may only be available for people living in groups in specific geographical areas such as cities, regions or states, with these groups becoming the unit of analysis for estimations of exposure levels and mortality rates. Causality cannot be established because information about the exposure of populations cannot be extrapolated to explain the outcomes for individuals. However, these studies are currently the major source of information regarding the health effects of hot weather and despite their limitations are relatively inexpensive, link available health data sets and environmental information, and are useful for hypothesis-generation and informing public health policy and programs. 25 3.2 Definition of Terms In this field of study, the definitions of a number of terms are contentious, or require qualification.

Therefore, while briefly defined here to allow better understanding of the review, they will also be discussed further in the following sections. A glossary of terms is also provided to assist the reader at the end of the review.

3.2.1 Elderly

While there is no international standard numerical criterion for the age at which a person becomes

‘elderly’, most developed countries accept this to be the arbitrary value of 65 years (12). For the purpose of this literature review, the term ‘elderly’ will refer to people who are aged 65 years or over.

3.2.2 Extreme hot weather

In this review, an episode of ‘extreme hot weather’ will be referred to as a ‘heatwave’. There is no standard definition of the term ‘heatwave’, with a variety of definitions used in the literature, each describing an event threshold and duration that are observed to be associated with increased morbidity and mortality of the population studied (13). A useful general description, for the purpose of this discussion is “a prolonged period of excessive heat” as defined by the Australian Bureau of

Meteorology (14).

3.2.3 Heat-related illness and death

The term ‘heat-related illness’ refers to a particular group of disorders caused by exposure to excessive environmental heat (15). These disorders include sunburn and fatigue, heat rash, heat cramps, heat syncope, heat exhaustion and heat-stroke (16). The most serious of these, heat exhaustion and heatstroke, can result in death (17). There are a number of definitions for ‘heat-related death’ found in the 26 literature. In all instances high ambient temperature is considered to be the major cause or contributing factor to the death (18-20).

3.2.4 Heat-associated illness and death

Not all the extra deaths and illness occurring in association with heatwaves are recognized as heatstroke, heat-exhaustion, or any other heat-related syndrome (21). Rather, much of the observed deaths and illness are due to an exacerbation of pre-existing illness. Therefore, the terms ‘heat-associated illness’ and ‘heat-associated deaths’ are used in this review to refer to the full spectrum of the health burden attributed to heatwaves.

3.2.5 Excess deaths

This is an expression of the number of deaths occurring over and above what would be expected for a particular population during a given time period, and is calculated by subtracting the expected mortality from the observed mortality (22). Using the measure ‘excess deaths’ avoids the problem of deciding which deaths are ‘heat-related’ and which are ‘heat-associated’ when assessing the mortality burden of heatwaves. 27 SECTION B: Background Information This section provides a discussion of background information relevant to the reviewed literature.

3.3 Human responses to extreme hot weather

3.3.1 Thermoregulation.

Thermoregulation refers to the process of regulation of body temperature (23). Within limits, humans are able to maintain their core body temperature within a very narrow range, despite alterations in ambient air temperature. This is necessary because elevation of core body temperature by just 4-5°C can cause nervous system malfunction, and disrupt enzyme systems (23).

Core body temperature is determined by the balance between heat gain and heat loss. Heat is gained as a byproduct of metabolic processes, skeletal muscle contraction and from the environment. Heat is lost to the environment by the processes of conduction, convection, radiation and evaporation (24).

Temperature regulating reflexes, initiated by stimulation of thermoreceptors, coordinated by the central nervous system, and mediated by the peripheral nervous system, activate heat loss or heat gain mechanisms (23).

Thermoregulatory mechanisms that promote heat loss and minimise heat gain during hot weather are physiological and behavioral. The physiological processes of sweating, and dilation of cutaneous blood vessels, are mediated by cholinergic fibres of the sympathetic nervous system via reflexes coordinated by the hypothalamus. Sweating achieves heat loss through evaporation; increased cutaneous blood flow promotes loss of heat through radiation, conduction and convection. Behavioral mechanisms include reducing activity, seeking cool environments, wearing appropriate clothing and using cooling devices

(25).

Thus, during excessive hot weather, maintenance of homeostasis through effective thermoregulation requires adequate functioning of numerous body systems, including the nervous, cardiovascular, and 28 musculo-skeletal systems. Integrated physiological responses involving neurological, renal and hormonal mechanisms are also required to maintain fluid and electrolyte balance despite loss of fluid through sweating, as are behavioral responses to the sensation of thirst. Effective behavioral responses to hot weather also require access to appropriate resources and cool environments.

The ability of the elderly individual to maintain a normal body temperature when exposed to a high ambient temperature can be compromised by a combination of the effects of ageing, chronic illness and disability, prescribed medication, and social factors. This is discussed further in Section F: 3.12.

3.3.2 Heat-related illness

The term ‘heat-related illness’ refers to a spectrum of disorders that can occur when the body’s thermoregulatory mechanisms are unable to compensate for exposure to excessive environmental heat

(19), such as that occurring in heatwaves. These disorders range from sunburn and fatigue, to heat cramps, heat syncope, heat exhaustion and heat-stroke (16). The most serious of these are heat exhaustion and heat-stroke, both of which can result in death (17).

3.3.2.1 Heat Exhaustion Heat exhaustion is an illness characterized by body fluid volume depletion resulting from an inadequate replacement of water and/or electrolytes lost during exposure to a hot environment, particularly through sweating (15). Signs and symptoms of heat exhaustion include intense thirst, heavy sweating, muscle cramps, anxiety, headache, dizziness, fatigue, nausea and vomiting (17, 26). Core body temperature may be normal, below normal or slightly elevated (27). If untreated, heat exhaustion can lead to heat stroke and death (17).

29 3.3.2.2 Heatstroke Heat stroke is defined clinically as a core body temperature greater than 40°C, accompanied by hot, dry skin and central nervous system abnormalities such as delirium, convulsions or coma (27). This definition is found consistently in the literature (28, 29), though Misset et al (30) choose to add that for heat stroke to be present there should be no other cause of hyperthermia, particularly infection, other than the ambient heat. Reflecting the postulated pathogenesis of heat stroke, an alternative definition, “a form of hyperthermia associated with a systemic inflammatory response leading to a syndrome of multiorgan dysfunction in which encephalopathy predominates”, has also been suggested (27).

Heatstroke can be rapidly fatal in a high proportion of cases, with many survivors having a poor outcome (28).

Box 2. Main points - The human response to extreme hot weather

 Core body temperature must be kept relatively constant, despite high environmental temperatures, to prevent damage to the nervous system.

 Promotion of heat loss and minimisation of heat gain during hot weather is achieved through physiological and behavioral responses.

 Thermoregulatory responses to hot weather must be accompanied by physiological and behavioral responses to maintain fluid and electrolyte balance despite loss of fluid through sweating.

 Maintenance of homeostasis during hot weather requires adequate functional capacity of numerous body systems including the nervous, cardiovascular, renal, musculoskeletal and hormonal systems, as well as behavioral responses supported by access to appropriate resources and cool environments.

 Thermoregulation in the elderly can be compromised by a combination of the effects of ageing, chronic illness and disability, prescribed medication, and social factors.

 A spectrum of disorders, known as ‘heat-related illnesses’, can arise when the body’s thermoregulatory mechanisms are unable to compensate for excessive environmental heat. The most serious of these are heat exhaustion and heat stroke, which can result in death.

30 3.4 How should deaths attributed to heat be defined and quantified?

3.4.1 Defining heat-related death

Most studies of the impact of extreme hot weather on human health have assessed the effect on mortality, since mortality data is often readily available. However a variety of definitions of the term

‘heat-related deaths’ are found in the literature (19, 20, 31, 32) (see Table 1 ), and many deaths occurring during heatwaves are not clinically apparent as being due to heat, with high ambient temperature playing an indirect role by precipitating failure of already compromised body systems (33).

For this reason, it is likely that heat-related deaths are underestimated. In one study, an estimate of

‘heat-related deaths’ was found to increase by 54% if deaths in which heat was regarded as a contributing factor were counted as well as those in which heat was regarded as the underlying cause

(19). In another, a heatwave in Chicago was found to have contributed to182 more deaths than had been defined as heat-related (31). Therefore, to avoid underestimation, the measure ‘excess deaths’ is often used to quantify mortality associated with heatwave events.

3.4.2 Defining & calculating excess deaths

The measure ‘excess deaths’ is used in a number of studies to quantify the mortality associated with heatwaves. It is an expression of the number of deaths occurring over and above what would be expected for a particular population during a given time period, and is calculated by subtracting the expected mortality from the observed mortality (22).

While using ‘excess deaths’ avoids the problem of deciding which deaths are ‘heat-related’ when assessing the mortality burden of heatwaves, methods found in the literature to estimate the baseline

‘expected mortality’ vary. For example, studies of the impact of the 2003 European heatwave on seven 31 different countries all used different methods for estimating the ‘expected mortality’, as described in

Table 3.

Also the calculation of excess deaths is sensitive to the period of time over which the measurement is made. For instance, in a study of mortality attributed to the 1995 Chicago heatwave, mortality was found to be 31% greater than baseline when calculated over one month, but 147% greater than baseline when calculated over one week (31).

This lack of a standardised method for calculating ‘excess deaths’ makes it difficult to compare the health impact of different heat events(1). Expressing excess deaths as a proportion relative to a calculated baseline provides a more useful measure with which to compare different heatwave mortality effects since it helps to control for the demographic characteristics of different populations

(31).

Box 3. Main points - The definition and quantification of deaths attributed to extreme hot weather

 Defining a death as attributable to hot weather is not straight-forward since many deaths occurring during heatwaves are not clinically apparent as being due to heat.  Deaths may occur as a direct consequence of exposure to high environmental temperatures, or may be due to failure of already compromised body systems.  The measure ‘excess deaths’ is often used to quantify mortality associated with heatwave events.

 ‘Excess deaths’ is as expression of the number of deaths occurring over and above what would be expected for a particular population during a given time period, and is calculated by subtracting the expected mortality from the observed mortality.

 Calculation of excess deaths is sensitive to the method used to calculate base-line deaths, and the period of time over which it is measured.

32 SECTION C: Extreme Hot Weather

3.5 Definition of ‘extreme hot weather’.

Key question 1: How should an episode of ‘extreme hot weather’ be defined?

For the purpose of this discussion, an episode of ‘extreme hot weather’ will be referred to as a

‘heatwave’. There is no standard definition of the term ‘heatwave’. The definitions found in the literature, range from very general (6, 14, 34) to highly specific (5). This is a reflection of the difficulty associated with developing a definition that not only describes a meteorological event, but must also incorporate the impact of the event on a given population (35). A sample of definitions found in the literature for the term ‘heatwave’ is provided in Table 2. A useful general description, for the purpose of this discussion is “a prolonged period of excessive heat” as defined by the Australian Bureau of

Meteorology (14).

The basic components of a heatwave definition are the event threshold and duration that are observed to be associated with increased morbidity and mortality of the population studied (13). The level of discomfort caused by hot weather is influenced by a number of meteorological conditions, including air temperature, humidity, cloud cover and air movement, as well as the level of physiological adaptation of those exposed (36). Some event thresholds are based on air temperature (5, 35, 37), while others are based on indices that incorporate temperature and humidity such as the ‘Apparent Temperature’ (38) and

‘Heat Index’(39), with the aim of heat stress indices being to predict heat wave weather conditions that may lead to adverse health effects, and to do so both simply and accurately (40).

Determining a universal definition of a heatwave would require nomination of a certain number of days that exceeded a pre-determined temperature or heat stress index level. However, this approach assumes that all populations respond similarly to heat stress. Relative approaches, however, take into account 33 differing levels of acclimatisation to weather and different responses to heat stress that are influenced by regional climate norms. In areas where hot and humid summer conditions are common, physiological, behavioral, and infrastructure adaptation is more likely and thus the harmful effects of heat stress may be reduced. Thus, what might be anomalous hot weather in a cooler climate like Hobart might be within summer norms in a warmer area like Adelaide (41).

The timing of a heatwave also affects its impact, with heatwaves that occur earlier in the summer season having been shown to have a greater impact on human mortality, before short-term acclimatization to hot weather has occurred (42). Also, night-time minimum temperatures have been found to have an important influence on health outcomes (43).

The lack of a simple meteorological measure to incorporate these complex interactions between the thermal climate and the human body precludes a universal definition of ‘heatwave’ and adds to the difficulty associated with comparing heatwave events, and analysing their frequency and severity over time (36).

Box 4. Main points - Definition of ‘extreme hot weather’

 For the purpose of this discussion, ‘extreme hot weather’ will be referred to as a ‘heatwave’.

 There is no universal definition for the term ‘heatwave’

 A general definition is “a prolonged period of excessive heat”.

 The basic components of a heatwave definition are event threshold and duration that are observed to be associated with increased morbidity and mortality of the population in question.

 Thresholds are values of meteorological conditions that reflect the vulnerability of the population under study, and can be temperatures or derived heat indexes

 Perception and health outcomes of heat are influenced by opportunity of the population to acclimatise, with responses differing between populations and within populations depending on location, timing within the summer period, and meteorological characteristics.

 Lack of a universal definition makes comparison of heatwave event and analysis of frequency of heatwave events difficult

3.6 The likely frequency and impact of heatwaves in the future.

Key question 2: Are heatwaves expected to occur more frequently in the future?

The fourth report from the Intergovernmental Panel on Climate Change (IPCC), a body recognized as the international authority on climate change, has concluded that there is no doubt global warming is occurring, and that this is very likely due to increases in atmospheric greenhouse gas concentration caused by human activities.

Over the past 100 years average global surface temperatures have increased by about 0.74°C, with most of this increase having occurred in the past 50 years. It is considered very likely that this global warming has been responsible for an increased frequency of hot days and nights, and of heatwaves, observed over the past 50 years (6). What is of particular concern is that even if it was possible for greenhouse gas emissions to be kept at current levels, global warming would continue for some time into the future due to persistence of accumulated greenhouse gases in the atmosphere(9).

The IPCC has predicted that hot extremes and heatwaves will become more frequent in the future, with average temperatures predicted to rise relative to 1990 about 1.0°C by 2030, and by up to 3.4°C by

2070(6). Increased average global temperatures are predicted to be accompanied by increased temperature variability (44). Furthermore, climate models for areas of Europe and North America predict that the heatwaves will become more intense and longer lasting (7).

According to the report “Climate Change in Australia”, recently released by the CSIRO and the

Australian Bureau of Meteorology, average temperatures in Australia have increased by 0.9°C since

1950, with an increased frequency of hot days and nights, and a decreased frequency of cold days and 35 nights. In Melbourne, the number of days each year over 35°C is predicted to rise from a current average of 9 days to up to 26 days by 2070 (45).

Such an increase could have a considerable impact on the health of Melbourne’s population, particularly if this increase includes more consecutive days of high temperatures. As evidence for this,

Loughnan (2008) has demonstrated that an average temperature (measured over 24 hours) of 27°C over three days would result in a 10-15% increase in admissions for myocardial infarction to Melbourne hospitals (46). Similarly, Nicholls et al (2008) has demonstrated that mortality in those age 64 years and older in Melbourne increases by 15-17% when the daily average temperature is >30°C, and by 19-21% when the daily minimum temperature exceeds 24°C (43).

In an assessment of risk to human health caused by climate change in the region of Oceania, projected rises in temperature are predicted to result in an increase in heat-related deaths in Australian cities. For

Melbourne, the number of heat-related deaths was predicted to rise from a baseline of 289 deaths per year to 1000-1300 per year by the year 2050, for people aged over 65 years(47).

However, this analysis is limited by the method used to calculate baseline mortality, and by the assumption of a linear relationship between mortality and temperature, which is unlikely during periods of sustained high temperatures(48). Also the influence of physiological and behavioral adaptation, economic change, and medical and technological advancement over this time period has not been considered.

Box 5. Main points - The likely frequency and impact of heatwaves in the future

Key Question 3: What has been the health burden from heatwaves in Australia and internationally?

Heatwaves and extreme hot weather are known to have a considerable impact on the health of exposed populations. For instance, it has been estimated that in Australia 4,336 people died between 1803 and

2002 as a consequence of heatwaves, twice the number of fatalities caused by cyclones or floods over the same period of time (47). In Queensland, 22 deaths and 350 injuries occurred during a heatwave in

January 2000, and in February 2004, 12 deaths and 221 hospitalisations were attributed to the heat (39).

In the USA, heatwaves are estimated to have caused about 400 deaths per year since 1998, more than that for any other natural disaster (49). The unprecedented heatwaves in Western Europe in 2003 have been estimated to have caused almost 70,000 additional deaths over the summer months (50), with most of these deaths occurring amongst the elderly (51).

The following discussion of studies investigating the health burden of extreme hot weather is divided into three sections: mortality, morbidity, and the Australian context.

3.7 Mortality Studies investigating the relationship between extreme hot weather and mortality fall into two main categories: those describing the short-term rise in mortality associated with specific heatwave events, and those that analyse the relationship between heat and mortality for particular populations over a more prolonged period of time in a time-series analysis (48).

Descriptive studies of specific heatwave events have provided information regarding the impact of heatwaves on mortality, and have analysed this for age and sex distribution (5, 31, 52-61), socioeconomic 37 status (58), cause of death (5, 52, 53, 55, 58, 59), place of death (5, 52, 54, 57-61), influence of concurrent air pollution (52, 54), lag times (31, 56, 58-60, 62), and evidence of mortality displacement (54, 59). Key descriptive studies are outlined in Table 4.

More information has come from time-series studies, including those have analysed data from one or a few summer periods, and those that have gathered large amounts of data over many years, often from populations in different geographic locations (4). The purpose of time-series analyses in this context has been to quantify the relationship between daily temperature and daily mortality, while controlling for potential confounding factors, such as time trends, seasonal cycles in daily mortality, and air pollution.

Since this type of analysis focuses on day-to-day changes in temperature and related mortality, only factors that vary over time can cause problems of confounding. The usefulness of time series analysis is that it allows many days to contribute to the calculation of baseline mortality, and the subsequent estimation of excess mortality, rather than just days defined as a heatwave.

Numerous time-series analyses have been reported in the peer-reviewed literature, describing the relationship between temperature and mortality from many perspectives including differences between cities or regions (63-72), between population groups within cities as defined by age, sex, race and socioeconomic status (63-65, 70, 71, 73-76), temperature thresholds for increased mortality (43, 65, 69, 77), patterns of cause-specific mortality (66, 77), lag times (68, 75) and mortality displacement (64, 67, 76) , and the influence of air pollution (76, 78), latitude (65, 69) and climate patterns (35, 63, 67, 72). Representative time- series studies are outlined in Table 5. Key findings from studies presented in Tables 4 and 5 are outlined in the following discussion.

38 3.7.1 Magnitude of impact of heatwaves on mortality.

Descriptive studies of specific heatwave events in the USA, Europe and the United Kingdom have shown that heatwaves are associated with marked short-term increases in mortality, with reported excess mortality ranging from 4% to 142% (31, 52-54, 58, 59, 62). However since heatwave events differ in terms of meteorological characteristics and exposed populations, and since the calculation of excess mortality is sensitive to methods used to generate baseline data and the period of time over which deaths are counted, it is not meaningful to compare one heatwave event with another. Nevertheless, a rise in mortality has been consistently reported for heatwaves occurring in the Northern hemisphere.

In contrast, a study of mortality data over 13 years in metropolitan Adelaide found no evidence of excess mortality occurring in association with heatwaves, other than a small increase in mortality for people aged 65 -74 years who had psychiatric illnesses. For people aged 75 years and over mortality decreased, with significant reduction in cardiovascular and respiratory deaths. The authors suggest this is a reflection of successful adaptation to heatwaves in Adelaide, particularly through the use of air- conditioning, and improved care of the elderly (79).

3.7.2 Age, sex and socioeconomic status of exposed population

Excess mortality associated with heatwaves has been observed to occur predominately in the elderly (54,

57-59, 80), and frequently (52, 53, 57, 59, 75, 80), but not always (31, 81), to be greater for women than for men.

The age group for which vulnerability to heat-related death is reported to be most pronounced varies, and is most commonly ≥ 65 years (31, 81, 82) , or ≥ 75 years (53, 54, 59). An exception to this is the 11% higher than expected number of deaths occurring amongst those aged 40-59 years in the Netherlands in the heatwave during August 2003. 39 A predominance of excess deaths amongst those of low education levels and low socioeconomic status has been observed in two large Italian cities (58).

3.7.3 Lag times

Lag times of 1-2 days (31, 56, 58), 1-3 days (59, 62) and up to 4 days (60) have been observed between the onset of a heatwave and the rise in mortality, suggesting that people succumb quickly to the effects of extreme heat. A high proportion of people have been found to have died at home, or before they could reach medical attention (83, 84).

3.7.4 Cause of death

Analyses of cause-specific mortality have revealed that not all (31, 53, 59), and sometimes very few (5) of the excess deaths occurring in heatwaves are directly attributable to the effects of excessive heat, but rather are due to the consequences of other illnesses. Cerebrovascular disease (52, 53, 84), cardiovascular disease (53, 55, 58, 81, 84), and respiratory disease (52, 53, 58) have frequently been reported to be predominant causes of death in heatwaves, with deaths due to diseases of the central nervous system (58), metabolic and endocrine disorders (58), and neoplasms (53) also mentioned. During the 2003 heatwave in France, accidental falls as a cause of death increased by 130% for those aged 75 years and over.

For the 2003 heatwave in Europe, diseases “directly linked to heat” were found to account for the largest proportion of the excess deaths in those aged 75 years and over in France (59), while in the

Netherlands only four deaths were attributed to exposure to “excessive natural heat”(5). The lack of a standard definition of heat-related death makes it difficult to compare results of these studies. 40

3.7.5 Place of death

An analysis of excess mortality by place of death in southern England during the 2003 heatwave found a disproportionately large fraction of excess deaths occurred in hospitals and nursing homes (61).

Similarly, a marked increase in deaths of the elderly in nursing homes was found in the Netherlands (5),

France and Italy (61), during the heatwave of the same year, when air-conditioning was uncommon in these facilities (85).

Studies of heatwaves in England in 1995 and 2003 reported the largest proportion of excess deaths to occur in the London area (52, 54). This has been attributed to higher night-time minimum temperatures associated with the heat-retaining properties of the city environment (the ‘urban heat island’ effect), higher levels of air pollution, and poor housing conditions (52).

3.7.6 Forward displacement of mortality

Theoretically, observed increases in mortality associated with extreme hot weather could represent the deaths of people who were already ill, and for whom inevitable death has been advanced by the hot weather, also referred to as ‘harvesting’ (64).

If this were the case it could be argued that much of the observed increase in mortality is not preventable. A number of studies have addressed this question by analysing the days immediately after heatwaves for excess mortality, since short-term advancement of mortality by hot weather could be expected to be followed by a period of mortality deficit. 41 Studies of heatwaves and extreme hot weather in England, Europe, the USA and Melbourne have found evidence of a small harvesting effect (54, 64, 75), or of no harvesting effect (43, 59, 73) , suggesting that most of the people who died in those situations would not have been expected to die in the short-term.

The extreme 2003 heat wave in France was associated with over 3000 excess deaths across nine French cities, but less than 10% of these appeared to represent short-term mortality displacement (64). This evidence supports the usefulness of implementing interventions designed to prevent mortality due to hot weather. On the other hand, others have found mortality associated with extreme hot weather to predominantly be a harvesting effect (86), highlighting the difficulties inherent in comparing heatwave events and the need for more research to determine how mortality displacement differs by city and within various subdivisions of the population.

3.7.7 Temperature thresholds for increased mortality

Adverse heat effects have been observed above a threshold temperature that represents the upper range of the local climate ‘‘comfort zone.’’ The threshold temperatures and comfort zone vary by locality, implying changing degrees of physical and/or biological acclimatisation to local weather phenomenon.

Analyses of the relationship between temperature and mortality in temperate climates have shown daily mortality rates to be lowest for an intermediate range of temperatures, as described by V or J shaped curves (77). The threshold temperature at which mortality increases varies with geographical location, with thresholds being higher in areas with warmer climates, and populations living in cooler climates being more sensitive to heat (65, 69). In the Northern hemisphere, cities at higher latitudes have been found to have lower threshold temperatures than more southern cities (65). There are no published studies investigating the relationship between threshold temperatures and latitude for the southern hemisphere. 42

3.7.8 Mortality and temperature variables

Time series analyses of the mortality-temperature relationship have shown the impact of heatwaves on the health of exposed populations is more pronounced with increased deviation of maximum day-time temperatures from those expected for that time of year (35, 76), with combined high maximum day-time temperatures and high night-time minimum temperatures (43, 48, 76), and with increased duration of the heatwave (35, 48, 87). Night-time minimum temperatures are more likely to be elevated in highly urbanized and industrial areas where heat-absorbing building materials, lack of vegetation and tall buildings limit over-night cooling (80).

3.7.9 Mortality and acclimatisation to hot weather

Heatwaves occurring early in the summer season have been reported to have a greater impact on health than those occurring later in the season (35, 80, 87, 88). Explanations suggested for this observation are that populations surviving heatwaves early in the season acquire physiological adaptation or institute behavioral change and infrastructure change, and that the most susceptible members of the population succumb to early heatwaves leaving a less susceptible population remaining (4).

The mortality observed in an individual heatwave is influenced by the level of acclimatisation of the exposed population. Analyses of the relationship between temperature and mortality in temperate climates have shown daily mortality rates to be lowest for an intermediate range of temperatures, as described by V or J shaped curves. (77). 43 Heat-related deaths occur more in areas where extreme heat is rare, hence the latitudinal effects noted in northern hemisphere studies, which are characterised by increased sensitivity to elevated temperature, and lower threshold temperatures defining heat events as distance increases from the equator.

Physical acclimatization can refer to a seasonal timeframe (lesser susceptibility in late summer than in early summer) or to a longer timeframe (number of years spent living in a region). The extent to which acclimatisation affects heat and mortality relationships has been studied by evaluating the effects of heat on death risk across different cities that vary in average summer temperatures and air conditioning usage.

Examining longitudinal records of daily deaths and weather in U.S. cities, revealed significant heat effects on mortality were reported mainly in northern U.S. cities (65-67). Similar results were observed in

London, and Sophia (68), and in the warm and cold regions of Europe (69), as well as between older people in North Carolina, Finland, and southeast England (63).The authors further reported that the prevalence of air conditioning was associated with diminishing heat effects. Supporting this view increased use of air conditioners resulted in decreased heat related mortality in US cities (72). These results suggest that air conditioning is likely to be an important adaptive mechanism.

3.7.10 Influence of air pollution

Some studies of heatwaves have concluded that concurrent increases in air pollution have contributed to a proportion of the observed excess deaths (52, 54). However research investigating the nature of the relationship between temperature, mortality and air-pollution has produced conflicting results, with further research required to ascertain whether there is an interaction between air pollution and 44 temperature, and if the effects of air pollution and high temperature on mortality are independent and additive (4).

In Australia, studies investigating the effects of air pollution on health have been conducted in

(89-93) Melbourne, Brisbane, and Sydney . The results of these studies have indicated that as PM10 (fine particles measuring less than 10μg/m3) increase, an increase in temperature produces an enhanced effect on cardio-respiratory morbidity and ‘all cause’ mortality (93). The effect existed on the current day and at different lags up to 3 days. The effects of outdoor air pollution on hospital admissions was investigated in Brisbane (94). The results indicated that in summer, ozone was consistently associated with hospital admissions for asthma and respiratory, cardiovascular, and digestive disease – with little evidence of a threshold. Particulate pollution was positively associated with admissions for asthma and respiratory disease in summer but was negatively associated with admissions for cardiovascular disease. Overall, ambient air pollution in Brisbane contributed to hospital admissions for asthma and respiratory disease. Although air pollution levels in Australia are generally lower than those observed in the US and Europe, the associations between ambient air pollution and mortality observed in overseas studies occur in Australian cities.

3.7.11 Modeling heat events

A range of temperature measures and methods has been applied to the description of heat extremes across studies and in the modeling structure of weather and mortality. Various statistical models can be applied to examine the climate-mortality or morbidity relationship. These require the use of a range of definitions of temperature exposure and mortality and morbidity outcomes. Individual meteorological variables are often used to determine the risk of weather-related mortality and morbidity. Many studies have proposed that ‘J’ or ‘U’ shaped curves best describe the temperature-mortality relationship, with increased effects noted at temperature extremes and lower mortality at moderate temperatures. Thus, 45 statistical models that do not assume normality or linearity are used to characterise these associations such as General Additive Models (GAM) and Poisson regression.

Measurement of weather conditions include the ambient temperature or the apparent temperature/heat index, which incorporates both temperature and humidity and is considered a measure of physical discomfort (48, 70-72, 74, 76). Minimum temperature (35, 48, 64, 76, 95), maximum temperature (35, 48, 64, 75, 95), and average daily temperature (35, 63, 65, 67, 68, 70, 73, 74, 76, 77, 95), have also been applied.

The health outcome of interest may be measured as total mortality (daily, monthly, or annually) (35, 48,

66-71, 75, 77, 95), excess number of deaths (63, 64, 72-74, 76), and percentage increase in mortality (35, 64, 74, 76), or relative risk of mortality in relation to heat events or threshold temperature (64-67, 75).

Generally, risk of death has been found to vary in a U-shaped fashion, with both winter cold and summer heat events being linked with increased deaths. While the U-shape is observed across multiple cities/regions, the temperature at which inflection points change on the U-shape does vary, as does the heat-related mortality slope (65) reinforcing the place specificity of temperature/mortality relationships.

The use of distributed lag model captures the delayed effects of heat on elderly persons and persons with chronic disease. The lag models also help evaluate whether the observed heat effects are the result of deaths being brought forward a few days (harvesting) or whether the temperature effects were having a longer-term impact. Typically, heat effects are immediate or represented by a short lag of up to 3 days (48, 64, 65, 67, 68, 70, 74), although longer lags are reported with regard to enhanced air pollution.

46 Box 6. Main points - Mortality and heatwaves

 Specific heatwave events in the Northern hemisphere have been associated with marked short-term increases in mortality, with reported excess mortality ranging from 4% to 142%. In contrast, a study in Adelaide found no evidence of excess mortality associated with heatwaves over a thirteen year period.

 Comparison of the health burden of different heatwave events is not meaningful due to differing characteristics of heatwaves, and exposed populations, and the differing methods used to derive ‘excess deaths’

 Excess mortality associated with heatwaves has been observed to occur predominately in the elderly, and frequently to be greater for women than for men.

 The impact of heatwaves on mortality is correlated with the extent to which temperatures deviate from the usual summer temperatures for that area, and the duration, intensity, and timing of the heatwave within the summer season.  Lag times of just a few days have been observed between the onset of a heatwave and the rise in mortality, suggesting that people succumb quickly to the effects of extreme heat.

 Not all, and sometimes very few of the excess deaths occurring in heatwaves are reported to be directly attributable to the effects of excessive heat, but rather are due to exacerbation of pre-existing illnesses, particularly cardiovascular and respiratory diseases, and diseases of the nervous system.

 There is evidence that only a small proportion of excess deaths occurring in heatwaves represent short-term mortality displacement.

 A disproportionately large fraction of excess deaths occurred in hospitals and nursing homes during the 2003 heatwave in Europe, when air-conditioning was uncommon in these facilities.

 Mortality associated with heatwaves has been reported to be greatest in city areas, in conjunction with observed high night-time minimum temperatures, high levels of air pollution, and poor housing conditions.

 Air pollution was found to have contributed to a proportion of the excess deaths occurring during heatwaves in England and Wales, though the nature of the relationship between air pollution and high temperature requires further investigation.

47 3.8 Morbidity Heatwaves and exposure to high ambient temperatures can cause illness as well as death. Heat-related illnesses include a spectrum of disorders ranging from sunburn and fatigue, to heat cramps, heat syncope, and potentially fatal heat exhaustion and heatstroke (17).

Also, exposure to hot weather may exacerbate existing chronic conditions. For instance, it is suggested that the requirements for an increased cardiac output to support increased cutaneous blood flow during thermoregulation may worsen cardiac failure(33), and heat-induced alterations in blood composition may promote thromboses in already narrowed coronary or cerebral arteries (96).

Few studies have investigated the effects of extreme hot weather on population morbidity. Those that have been published include analyses of hospital emergency department presentations, hospital admissions, ambulance calls, and survival rates of heat-stroke patients, and are outlined in Table 6

3.8.1 Hospital admissions

Total emergency hospital admissions are reported to have increased by 11% during a heatwave in

Chicago in 1995 (97), and not at all during a heatwave of the same year in Greater London (83). In marked contrast, the excess mortality reported for the same periods of time in these cities was considerably higher: 147% for Chicago (31) and 16% for Greater London (52). While this discrepancy could be due to chance or measurement bias (98), one explanation proposed is that many people dying during heatwaves have a rapid decline in health leading to their death before they are able to reach hospital, or before they are noticed by others (1, 83).

Significant increases in hospital admissions for treatment of heat-related illness and acute renal failure, but not for cardiovascular, cerebrovascular or respiratory disease were observed in the 1995 Chicago heatwave (97). This is in contrast to known causes of death in heatwaves (21). An analysis of primary and 48 secondary discharge diagnoses, however, revealed that it was individuals with pre-existing cardiovascular disease, diabetes, renal disease, or nervous system disorders who were at most risk of hospitalization for treatment of heatstroke, heat exhaustion and acute renal failure (97, 99), which more closely reflects observations from mortality studies. It has been speculated that acute renal failure, a predominant reason for increased hospital admissions in this study, may occur as a complication of heatstroke (21).

A study from Adelaide found that emergency hospital admissions were on average 7% higher during heatwave than non-heatwave periods over a 13 year period (79). Increased admissions were observed for all age groups over 15 years, and were predominately due to increased admissions for mental-health related conditions and renal disease. No distinction was made between acute and chronic renal disease in this study. No significant increases were seen in total hospital admissions for cardiovascular disease or respiratory disease. Admissions for treatment of ischaemic heart disease did increase by 8% for those aged 65-74 years. However, for the ≥ 75 years age groups admissions for both ischaemic heart disease and respiratory disease fell. No analysis of secondary discharge diagnoses, an indication of comorbidity, was included. Interestingly, over the period of this study no excess mortality was observed during heatwaves, and for people aged ≥75 years, mortality decreased, with significant reduction in cardiovascular and respiratory deaths. The authors suggest this is a reflection of successful adaptation to heatwaves in Adelaide, particularly through the use of air-conditioning, and care of the elderly.

A study of the relationship between hospital admissions and intensity, duration and timing of heatwaves across the summer months in Italy found that heatwave duration rather than intensity or timing was the major risk factor for hospitalisation for heat-related diseases and respiratory disease

(100). In this study, at least four consecutive, hot, humid days were required before a large increase in 49 hospital admissions was observed, with heat-related diseases being defined as disorders of fluid and electrolyte balance, acute renal failure, and heat stroke.

3.8.2 Ambulance transportation

Ambulance transports increased by 4% in Adelaide on heatwave days(79), and ambulance calls increased by 10% in Toronto on oppressively hot days (101). In Adelaide, ambulance transportation increased particularly for assault-related injuries, while cardiac-related transports for those aged ≥75 years decreased.

An analysis of the spatial distribution of ambulance calls in Toronto found that during very hot weather the greatest increase in calls was from the inner city (especially on weekdays), lake-side recreation areas, and older industrial areas where housing was older, and residents were more likely to be elderly, immigrants, or from minority groups. Of particular interest, (and perhaps relevance to Victoria,

Australia), was the consistently significant increase in ambulance calls from Toronto Island during hot days. This island, which has a small population of permanent residents, one ambulance and no hospital, experiences a marked increase in population during the summer months since it is a holiday destination for city residents seeking to avoid the hot weather (101).

3.8.3 Heatstroke

Studies of patients admitted to hospitals during heatwaves for treatment of heatstroke have shown this illness to be associated with a poor short and long-term outcome. It is more likely to occur in people 50 with underlying chronic medical conditions, who are taking medications, and who become ill at home(28-30).

The in-hospital mortality of heat-stroke patients in Chicago hospitals during the 1995 heatwave was

21% (29), while 63% of heatstroke patients admitted to intensive care units in France during the heatwave in 2003 died, with a mean survival time of just 13 days (30). 58% of heatstroke patients admitted to a large hospital in Lyon during the same heatwave were reported to have died by 28 days, while 71% had died by 2 years, with most survivors assessed as having a deteriorated functional status

(28). Similarly, for the Chicago heatwave, 28% of those discharged from hospital had died after 1 year, and no survivors had an improved functional status (29).

Most patients with heatstroke who were admitted to Chicago hospitals were found at home, had underlying chronic medical conditions, and were taking at least 1 type of medication before admission, usually diuretics. Common underlying diseases were hypertension, alcoholism, coronary heart disease and diabetes(29).

A similar profile was found for those admitted to hospital in Lyon: most were older than 70 years, had major functional limitations, at least 1 chronic medical condition, and were being treated with antihypertensive or neurotropic medication. The most common underlying illnesses were cardiovascular, neurological and psychiatric disease, and the most commonly used medications were diuretics and tranquilisers (28).

In France, poor prognostic factors included being discovered ill at home or in a care facility rather than a public place, having a severe clinical profile at admission, and being treated in an intensive care unit without air-conditioning (30). In the Chicago study long-term risk of death was greater for those with higher levels of functional disability at discharge(29). 51

Box 7. Main points - Morbidity and heatwaves

 Few studies have investigated the effects of extreme hot weather on population morbidity

 Hospital admissions have been observed to increase during heatwaves; however studies have revealed discrepancies between the impact of heatwaves on morbidity and mortality, in terms of magnitude, cause, and age group.

 Reports of a lesser impact of heatwaves on hospital admissions than on mortality may indicate that people die quickly during heatwaves before they are able to reach hospital or be noticed by others.

 An analysis of underlying cause of admission, has demonstrated that individuals with pre-existing cardiovascular disease, diabetes, renal disease, or nervous system disorders are at most risk of hospitalization for treatment of heatstroke, heat exhaustion and acute renal failure.

 Studies of patients admitted to hospitals during heatwaves for treatment of heatstroke have shown this illness to be associated with a poor short and long-term outcome.

3.9 The Australian Context

According to the report “Climate Change in Australia” released by Australia’s Commonwealth

Scientific and Industrial Research Organisation (CSIRO) and Bureau of Meteorology, average temperatures in Australia have increased by 0.9°C since 1950, with an increased frequency of hot days and hot nights (45). An assessment of risk to human health caused by climate change in the region of

Oceania suggests that projected temperature increases will result in an increase in heat-related deaths in

Australian cities (47).

A comprehensive study undertaken to quantify the relationship between climate and mortality in the five largest Australian cities has reported an upper threshold maximum temperature, above which mortality increased, of 28°C for all five cities (102). It also predicted 175 additional deaths (from all cause mortality) annually, in association with days exceeding the 28°C threshold (102). The consistency of upper thresholds between 280 - 300C reported by other studies for Melbourne (43, 46), Hunter Valley 52 (103) and Brisbane (104) provides evidence that thermal stress occurs in susceptible populations at approximately 280- 300C in eastern Australian cities.

A study of the relationship between temperature and morbidity in Melbourne has demonstrated that an average temperature over 24 hours of 300C would result in a 4-10% increase in myocardial infarction

(MI) admissions to Melbourne hospitals, and an average temperature of 270C over three days would result in a 10-15 % increase in MI admissions (46). Spatial analysis of MI hospital admissions on days exceeding these threshold temperatures has demonstrated a relationship between the Urban Heat Island

(UHI) and place of residence of those admitted for MI (46). This is of relevance for the Melbourne 2030 urban development plan which is expected to increase the effects of the UHI in the inner city suburbs

(105). In addition, this study also demonstrated an inverse relationship between areas of low socioeconomic status and areas of increased MI admissions on both single and consecutive days of hot weather (46). Also, it has been found that mortality in the elderly (64 years and older) in Melbourne increased by 15-17% when the daily average temperature was greater than 300C, and increased by 19-

21% when daily minimum temperature exceeded 240C (43). Therefore, it is known that in Melbourne a mortality/morbidity –heat relationship exists, and that population vulnerability is influenced by socioeconomic status and age, and that the UHI enhances the effect.

Melbourne has a dynamic climate and periods of extreme heat may come to an abrupt end with the passage of a cold front resulting in a very rapid drop in temperature of 10-15°C within an hour. Days of extreme heat rarely last longer than 3-5 days (106). The number of days each year in Melbourne over

35°C is predicted to rise from a current average of 9 to 26days by 2070 (45). Should this increase include more consecutive days of increased temperature, then the impact on human health would be even greater.

A heat wave occurred in Melbourne in the January and February of 1959, when two episodes of excessive heat occurred within a 3-week period. The initial heat event took place during mid-summer 53 and claimed 74% of the total mortality. The deaths declined sharply to pre-heatwave levels immediately after the heat events (106). These observations are consistent with the results of studies from the Northern hemisphere. Australian cities, in particular Melbourne, demonstrate threshold temperatures above which mortality increases.

Conversely, unlike European and US cities, the threshold temperature in eastern Australian cities is relatively consistent irrespective of latitude and daily/seasonal temperature ranges. Analyses of autopsy reports in Australia from 1991-1998 found excessive clothing, prolonged sun exposure, acute alcoholic intoxication, obesity, medication use, and alcoholic liver disease were all predisposing factors to heat related mortality/morbidity(107). This may indicate that compositional and contextual influences on population health may account for differences noted in northern hemisphere studies.

Box 8. Main points -The Australian Context

 It is predicted that increased global temperatures associated with global climate change will result in an increase in heat-associated deaths in Australian cities.

 A threshold maximum temperature above which mortality is observed to increase in eastern Australian cities is approximately 28-30°C.

 In Melbourne, a relationship has been observed between morbidity, mortality and temperature, with population vulnerability being influenced by age, socioeconomic status, and location of residence with regard to the urban heat island.

 An average temperature of 30°C has been has been shown to result in a 4-10% increase in admissions for myocardial infarction to Melbourne hospitals.

 In Melbourne, thresholds of daily average temperature greater than 30°C, and daily minimum temperature greater than 24°C, have been found to be associated with increased mortality rates for those aged 64 years or older.

 The results of Australian studies are consistent with those from the Northern hemisphere, except that threshold temperatures above which mortality increases in eastern Australia are relatively consistent irrespective of latitude and daily or seasonal temperature ranges.

SECTION E: Risk factors for heatwave-associated illness and death

Key Question 4: What factors influence the risk of death and illness occurring in association with an episode of extreme hot weather?

Studies of the characteristics of exposed populations and their environment that affect risk include case-control studies that compare the characteristics of those who have died in heatwaves with those who survived (20, 84, 108-111), a meta-analysis of case-control studies (112), a case-crossover study (113) designed to detect transient changes in risk during brief exposure to hot weather (114), and case-only studies that compare the characteristics of those dying on hot days with those dying on other days (115,

116). Details of a number of these studies are outlined in Table 7. A summary of factors found to be associated with an increased risk of heat-related death, or protective against heat-related death, as indicated by estimated odds ratios, are presented in Tables 8 and 9, respectively. The following section outlines findings from the literature regarding factors that increase the risk of heat associated morbidity and mortality, and factors found to be protective.

3.10 Factors that increase the risk of death and illness associated with heatwaves.

Factors that increase the risk of illness and death during heatwaves include characteristics of the heatwave event itself, as well as characteristics of the exposed individuals, and the environment in which they live. 55 3.10.1. Characteristics of heatwave event

As previously discussed, characteristics of heatwaves found to be important regarding health outcomes of exposed populations are the extent to which temperatures deviate from the usual summer temperatures for that area (76), duration, intensity, and timing of the heatwave within the summer season

(35). Thus, episodes of hot weather posing the greatest threat to exposed populations are those characterised by several days of temperatures much hotter than usual for that location, with hot nights

(76), and occurring early in the summer period.

3.10.2 Characteristics of exposed individuals

Descriptive studies of heatwave events have consistently shown the elderly to be predominant amongst those dying or becoming ill during heatwaves. A meta-analysis of case-control studies has identified being confined to bed, not leaving home daily, and being unable to care for one-self to be characteristics of those at greatest risk (112). These and other characteristics of individuals found to increase susceptibility to poor health outcomes during heatwaves are discussed in the following sections.

3.10.2.1 Age Most studies of mortality associated with heatwaves and hot weather have shown that the excess mortality is most pronounced in the elderly. Studies vary in terms of the age above which a significantly increased risk of dying is reported, and is most commonly ≥ 65 years (31, 75, 82) or ≥ 75 years (54, 59). The actual age at which vulnerability starts to increase has not been investigated, with these age groups being predetermined categories used in the data analysis (117). It is also unclear if there is a difference in risk between the young old (65 to 74 years), old (75 to 84 years) and very old (85 years and over). It would seem reasonable to speculate that the risk increases with each age grouping.

55 56 Young children, especially those younger than 4 years old, are also regarded as being at increased risk of dehydration and heat stroke (17, 118). During the period 1979 – 2002, 6% of all heat-related deaths attributed to weather occurred among children aged less than 15 years of age, with a number of these deaths occurring in locked cars (26). However time-series and episode analyses have shown little evidence of excess mortality amongst children during heatwaves (59, 108, 119).

3.10.2.2 Social isolation Living alone (20, 108), not leaving home each day (20), being a widow or widower (113), and not having social contacts (109) are all strongly associated with an increased risk of death during heatwaves. For instance, in one study, the complete absence of social contacts multiplied the risk of death six-fold (113).

3.10.2.3 Being dependent on others for care Indicators of dependence found to be associated with an increased risk of death include being confined to bed (20, 109, 112), being unable to care for ones-self (20, 109, 112), receiving assistance in the home from public agencies including Nurses and Meals on Wheels (20, 84), and the loss of at least one activity of daily living (84). Being confined to bed has consistently been found to be a major risk factor, with one study finding this multiplied the risk of death during heatwaves more than seven times (109).

3.10.2.4 Pre-existing illness Numerous studies have identified having chronic illness or pre-existing illness at the time of a heatwave as being a risk factor for heat associated mortality (20, 84, 108, 109) and morbidity (28, 97, 120). Pre- existing illnesses found to be most strongly associated with dying during a heatwave are cardiovascular disease (20, 108, 109, 112), psychiatric illnesses (20, 108, 109, 111, 112), cognitive impairment (84), and neurological disease (109). Also found to increase risk are respiratory disease (20), diabetes (116), cancer (109), and obesity (109). Indeed, it is reported that most excess deaths occurring during heatwaves are attributed to exacerbation of existing illness (52, 53, 59) .

56 57 These illnesses, and medications used in their treatment, may increase vulnerability through compromising thermoregulation, mobility, awareness of a hot environment, or the ability to adopt protective behaviors (121). Increased blood viscosity and cholesterol concentration, due to haemoconcentration resulting from increased loss of water and electrolytes in sweat, is thought to be the underlying mechanism explaining the increased mortality due to coronary and cerebral thrombosis observed in hot weather (96). Pre-existing cardiac failure may be worsened by cutaneous vasodilation accompanying the thermoregulatory response to excessive heat (122), and there is evidence that impaired autonomic nervous system function can compromise thermoregulation through altered control of cutaneous vasodilation, and diminished ability to sweat in those with diabetes (116, 123). Dementia and other neurological conditions leading to cognitive impairment may lead to difficulties caring for ones- self, obtaining drinks, asking for help, and using an air conditioner.

There are a number of reports of people with psychiatric illnesses being at greater risk of heat-related illness and death (88, 111, 124), including a meta-analysis which found that a pre-existing psychiatric illness tripled the risk of death (112). Reasons proposed for this increased vulnerability include the physiological effects of altered neurotransmitter activity, increased agitation, lack of access to air- conditioning, inadequate care or the patient’s lack of understanding of precautions to take during heatwaves (88). A number of antipsychotic drugs are known to interfere with normal thermoregulation through anticholinergic effects, causing diminished sweating, or central thermoregularory effects altering the hypothalamic temperature set-point (124). Use of recreational drugs can also increase vulnerability to heat-related death (125), with methylene-dioxyamphetamine (Ecstasy), amphetamines and cocaine increasing metabolic heat production , and alcohol causing central nervous system depression and diuresis leading to sedation and dehydration (124).

57 58 3.10.2.5 Lower socioeconomic status Increased risk of death during heatwaves has been reported for people of lower socioeconomic status

(58, 108, 109). Lower socioeconomic status may increase vulnerability to heatwave associated mortality because of reduced access to adequate housing, inability to purchase air-conditioning, inability to pay for electricity needed to operate air-conditioners, lack of transportation to cooler locations and medical assistance, and associated behaviors such as alcoholism and drug abuse (58).

3.10.2.6 Homelessness Excess deaths and morbidity have been reported for homeless individuals in association with heatwaves in Arizona (126) and Adelaide (127). 14 of the 18 heat-associated deaths that occurred during a heatwave in Phoenix in 2005 were of homeless people. Factors contributing to the increased vulnerability of individuals with insecure housing include lack of access to shade, drinking water, and air-conditioned shelter (126, 127), little access to sources of information about the heatwave such as television, radio, newspaper or internet (128), as well as associated psychiatric disorders, drug and alcohol abuse, and chronic illness (121).

3.10.3 Characteristics of environments in which people live

Characteristics of environments in which people live that have been found to increase vulnerability to poor health and death associated with heatwaves are discussed in the following sections.

3.10.3.1 Geographic location Those residing in geographic locations with variable weather patterns, and cooler climates, have little opportunity to acclimatize to high temperatures and are therefore vulnerable to the adverse health effects of heatwaves (65, 67).

58 59 3.10.3.2 Cities A number of studies have reported excess mortality to be greater in cities than for surrounding areas (52,

129). This is attributed to the ‘urban heat island effect’, and the effect of concurrent air pollution (52). The combination of dark coloured heat-absorbing road and building materials, lack of cooling vegetation, reduced airflow between closely built buildings, and the generation of heat by cars and factories contributes to the development of urban heat islands in which day-time and night-time temperatures are higher than surrounding rural areas. Higher temperatures persisting for longer periods of time, due to the diminished opportunity for night–time cooling, leave residents more vulnerable to adverse health effects of heatwaves (130, 131).

3.10.3.3 Housing Living on the top storey of a multi-storey building, and having a bedroom directly under the roof of a house have both been found to be significant risk factors for heat –related illness and death, as has residing in older buildings without insulation (109).

59 60 Box 9: Main points - Factors that increase risk of death and illness associated with heatwaves

 Episodes of hot weather posing the greatest threat to exposed populations are those characterised by consecutive days of maximum day-time temperatures much hotter than usual for that location, with hot nights, and occurring early in the summer period.

 Characteristics of individuals found to be most strongly associated with an increased susceptibility to poor health outcomes during heatwaves are being : . aged 65 years or older, . socially isolated, . dependant on others for care particularly if confined to bed, . poor, . homeless, . and having a pre-existing illness.

 Pre-existing illnesses most strongly associated with an increased risk of death during heatwaves are cardiovascular disease, psychiatric illness, cognitive impairment and other neurological disorders, respiratory disease, cancer, diabetes and obesity. These illnesses, and medications used in their treatment, may increase vulnerability through compromising thermoregulation, mobility, awareness of a hot environment, and the ability to adopt protective behaviors.

 Characteristics of environments in which people live that have been found to increase the risk of death associated with heatwaves include living in geographical locations with variable weather patterns, living in cities, and living in housing that lacks insulation, and has bedrooms located directly under the roof.

60 61 3.11 Factors that decrease the risk of death and illness associated with heatwaves.

Factors found to be most strongly associated with a reduced risk of dying during a heatwave are having a working air conditioner in the home (20, 108, 111, 112), visiting other air-conditioned locations (20, 112), and participating in social activities (20, 108, 112). Also, having a pet in the home (20, 108), having access to transport (20), dressing lightly (109), and taking extra baths or showers during a heatwave (108) have been reported to be protective. A meta-analysis of six case-control studies identified having a working air- conditioner to be the strongest protective factor against death, followed by visiting cool environments, and participating in social activities (112). The study was inconclusive regarding the optimum number of hours to be spent in a cool environment, but did reinforce the importance of removing elderly vulnerable people from high ambient temperatures during a heatwave.

3.11.1 Fans

Two studies have reported that while use of air-conditioners was protective, use of electric fans was not (20, 108). Fans move air past the skin, and can induce heat loss by facilitating convection and evaporation of sweat (23). However, as the ambient temperature rises, air flow becomes a less efficient way of promoting heat loss through convection since the temperature gradient between skin and air decreases (132). Also, cooling through evaporation becomes less efficient as air humidity rises (40).

Therefore, fans are not considered to be protective against heat-stroke when ambient temperature reaches 32.2°C, and humidity exceeds 35% (133). It has been suggested that use of fans when temperature and humidity exceeds these parameters may be harmful since movement of air that is warmer than normal body temperature over the skin may raise skin temperature and increase core body temperature (112). In this situation the increased circulation of hot air can promote excessive evaporation of sweat, and speed up the onset of heat-exhaustion (126). Consequently some public health agencies,

61 62 such as Toronto Public Health, recommend that fans should only be used near open windows allowing cooler air to enter a room and hot air to leave (134). The United States Environment Protection Authority discourages the use of fans in homes that lack air-conditioning and are already hot, unless they can be used to bring cooler air into the building, recommending measures such as taking frequent cool showers and drinking iced water instead (126).

Box 10: Main points - Factors that decrease risk of illness and death associated with heatwaves

 Factors found to be most important for decreasing the risk of death associated with exposure to heatwaves are

. having a working air-conditioner, . visiting other air-conditioned locations during the heatwave, . participating in social activities

 Fans are not regarded as effective against heat stroke when ambient temperature exceeds 32°C, particularly when accompanied by high humidity (over 35%). The use of fans when temperature and humidity exceeds these parameters in closed environments may raise skin temperature, promote excessive evaporation of sweat, and speed up the onset of heat-exhaustion.

 It is recommended that fans should only be used near open windows allowing cooler air to enter a room and hot air to leave.

62 63 SECTION F: Vulnerable groups

Key Question 7: Which population groups are at most risk of harm from extreme hot weather?

The vulnerability of populations to heatwaves depends on characteristics of the extreme weather events, the exposed individuals, and the environment in which they live.

In theory, vulnerability to extreme hot weather will be increased in individuals with compromised physiological responses to excessive heat, those who have reduced ability to modify their behavior in order to care for themselves or reduce their exposure to hot weather conditions, and those who have limited access to resources such as air-conditioners, shelter, transportation, cool spaces, and drinking water.

Population groups identified in the literature as being most vulnerable to harm during heatwaves are (20,

26, 112, 117, 126, 133):

 the elderly,  the very young,  those taking certain prescribed medications (especially diuretics, anticholinergic agents, tranquilizers (26)),  people with chronic illness (especially cardiovascular disease, pulmonary disease (26, 112)),  people with psychiatric illnesses,  people with illness or disabilities that restrict their mobility  the homeless,  people who are socially isolated,  those who are economically deprived,  those who abuse alcohol or illicit drugs (especially cocaine or amphetamines (26))  people who engage in vigorous outdoor exercise or work

In the following section, factors contributing to the increased vulnerability of the elderly to adverse health outcomes during extreme hot weather will be addressed.

63 64

3.12 Vulnerability of the elderly to extreme hot weather.

Key Question 6: Why are the elderly particularly vulnerable to extreme hot weather?

A combination of factors diminish the elderly individual’s capacity to maintain a normal body temperature and adequate hydration during extremely hot weather, thus making them vulnerable to heat-related illness. These include the effects of ageing, chronic illness and disability, prescribed medication, and social factors.

3.12.1 Effects of ageing

3.12.1.1 Thermoregulation Compared with younger adults, older individuals have been found to have reduced sweat gland output, decreased skin blood flow, reduced cardiac output, and smaller redistribution of blood flow from spleen and kidneys to skin, during heat stress (135). These factors would all contribute to less efficient heat-loss through peripheral vasodilation and sweating. More research needs to be done to clarify whether these observations are a consequence of ageing alone, or due to concomitant disease and lack of fitness.

Observed gender differences in the cardiac response to heat stress, with older women having a higher stroke volume than men, also warrants further investigation (135).

3.12.1.2 Thirst mechanism It has been found that people over 65 years of age don’t drink as much in response to dehydration as do younger subjects. Although the sensation of thirst is thought to be as intense, satiation of the thirst sensation occurs earlier for a smaller volume of ingested water. This is thought is be caused by age- related alterations in the part of the brain responsible for the sensation of thirst (136).

64 65 3.12.1.3 Renal function Age-related changes in renal function cause a diminished ability to conserve water and salt through the production of a concentrated urine, thus accentuating the effects of dehydration (137). Also, decreased responsiveness of the renal hormonal systems to electrolyte imbalance is postulated to contribute to cardiac arrhythmias and increase the risk of thrombo-embolic disease (138). Diseases such as diabetes and hypertension, more common in the elderly, have been found to accelerate the process of renal ageing (137).

3.12.1.4 Reduced fitness Level of fitness, as measured by maximum oxygen uptake, has been found to be an important factor influencing the response to heat stress of individuals placed in warm, humid environments (139). For a given heat stress, fitter subjects have been found to have a more efficient sweating response, with more efficient skin cooling and smaller elevations in heart rate (139). Fitness in healthy, sedentary individuals is reported to decline by about 10% per decade after the age of 20 years (140). A low level of fitness, due to reduced levels of physical activity, is regarded as an important factor increasing the vulnerability of the elderly to harm during hot weather (118).

3.12.2 Chronic illness and disability

A number of chronic illnesses that are associated with an increased risk of death during heatwaves are also more prevalent amongst those aged 65 years and over. For instance, data from the Australian

Bureau of Statistics reveal that in Australia, cardiovascular disease (141), cancer (142), diabetes (143), and dementia (144) are all more prevalent in the older age groups. Rates of disability requiring assistance with activities of daily living also increase with increasing age, particularly for those aged over 80 years (145).

65 66 As previously explained, these chronic health problems in conjunction with medications used in their treatment, may increase vulnerability to hot weather through compromising thermoregulation, mobility, awareness of a hot environment, or the ability to adopt protective behaviors (121).

3.12.3 Prescribed medications

Medications that can contribute to adverse health outcomes during heatwaves include diuretics which promote fluid loss and may exacerbate dehydration in hot weather, anti-cholinergic agents (e.g., tricyclic antidepressants, antihistamines, some anti-parkinsonian drugs) that reduce the ability to sweat, antipsychotic drugs which act on the central nervous system to alter the thermoregulatory set-point, and tranquilizers which may alter the usual behavioral response to heat (124, 133). These categories of medication are commonly prescribed for management of illnesses in the elderly.

3.12.4 Social factors

Social isolation has been strongly associated with an increased risk dying during a heatwave (20, 108, 113), and a large proportion of elderly people live alone. The Australian Bureau of Statistics has estimated that there will be between 2.8 million and 3.7million lone person households in Australia by 2026.

Between one-quarter to one-third of all people living alone (between 844,000 and 962,000 people) will be aged 75 years and older, with three-quarters of these people being women (146). Risk factors for social isolation include loss of partner, poor health, mental illness, being a carer, living in an isolated rural area, not speaking English as a first language, being fearful of assault, and lacking access to suitable public transport (147).

66 67

Box 11: Main points - Vulnerability of the elderly to extreme hot weather

 A combination of factors diminish the elderly individual’s capacity to maintain a normal body temperature and adequate hydration during extremely hot weather, including the effects of ageing, chronic illness and disability, prescribed medication, and social factors.

 Age-related changes to the thermoregulatory response include reduced sweating, decreased skin blood flow, reduced cardiac output and smaller redistribution of blood flow from spleen/kidneys to skin during heat stress.

 Chronic illnesses known to be associated with an increased risk of death during heatwaves are more prevalent in the elderly. These illnesses, and medications used in their treatment, can increase vulnerability to hot weather through compromising thermoregulation, mobility, awareness of a hot environment, or the ability to adopt protective behaviors.

 A number of medications used for management of illness in the elderly can contribute to adverse health outcomes during heatwaves through promoting fluid loss, interfering with thermoregulatory mechanisms, or causing sedation.

 A large proportion of elderly people live alone. Social isolation is a risk factor for death during heatwaves, and can occur as a result of loss of partner, poor health, mental illness, being a carer, living in an isolated rural area, not speaking English as a first language, being fearful of assault, and lacking access to suitable public transport. .

67 68 SECTION G: Harm Minimisation Strategies

Key Question 7: What strategies have been adopted to reduce harm to the elderly due to extreme hot weather?

In response to observations of the considerable health burden associated with heatwaves (50), analyses of the public health response to heatwaves in Europe in 2003 (148), and predictions of more frequent heatwaves in the future (6), a number of governments and health agencies have developed heatwave harm minimisation strategies. The usefulness of developing such strategies is supported by evidence suggesting that little of the excess mortality attributed to heatwaves is due to short-term forward displacement of deaths (43, 59, 73).

Harm minimisation strategies include public education to promote modification of individual behavior using health education programs or written behavior guidelines, the more comprehensive heatwave response plans that use meteorological forecasts to initiate public health interventions, and long-term prevention strategies such as building design and urban planning.

3.13 Public education

Public education initiatives include health education programs and the dissemination of guidelines for personal strategies to minimise harm from heatwaves. Education programs include those provided for the general public, those directed towards high risk groups, and those provided for health care providers. Some heatwave response plans include education programs. For example, as part of the

Toronto Hot Weather Response Plan, education programs are provided by Toronto Health at the beginning of summer for the general public and staff of health care organisations (149). The education

68 69 programs include seminars, displays and posters. Groups targeted include elderly citizens’ organisations, childcare providers, schools, and landlords of rooming houses and boarding homes. In addition, the Canadian Red Cross conducts first-aid training for staff and volunteers of community agencies serving vulnerable people. In Shanghai, official presentation are made early in summer for the general public, the elderly, and those who work in hot environments regarding hot weather and health.

Doctors are also reminded to pay attention to the adverse effects of some medications during hot weather (150).

A number of health departments and health agencies publish guidelines for personal strategies to assist members of the public minimise the health effects of extreme heat for themselves and those around them through modification of their own behavior.

This information is found on web-sites, in leaflet form or in media releases, and can be available all year round or only when a heat-related health threat is declared imminent. Generally, information provided includes personal behavior strategies regarding fluid intake, appropriate clothing, seeking cool shelter, reducing activity, and use of air conditioners and fans, symptoms of heat-related illness, details of high risk groups, and advice regarding when and how to seek further information.

Also, people are advised to check on elderly or unwell neighbours and friends. This advice may be general or quite specific. For example, the guidelines from the Centers for Disease Control (CDC) recommend that during a heatwave, elderly friends and neighbours should be checked on at least twice a day (151).

Some organisations also have more detailed publications covering specific topics such as heat stress and the elderly, summertime blackouts, use of fans, pets and heat, and car safety in the heat (151, 152).

The Center for Diseases Control and Prevention publication ‘Safety in a Power Outage’ focuses on loss of power during extreme summer heat, since without air-conditioning this is regarded as “a disaster

69 70 within a disaster” (153). It is recommended that in preparation for such a situation, people develop a personal emergency plan that includes a disaster supply kit with three days supply of water and food

(154). A number of publications are available in different languages, and large print. Examples of published guidelines for personal strategies during heatwave are provided in Table 10.

A number of commentators however, consider it unlikely that the passive dissemination of information such as this will be effective if unaccompanied by more active outreach to vulnerable groups(1, 22).

Those who are most at risk of poor health outcomes during a heatwave, that is, those who are elderly, socially isolated, and who suffer from chronic illness, physical disabilities or cognitive impairment, may be unable to access or act upon this type of information (118).

Box 12: Main points - Public education

 A number of Government Health Departments and health agencies provide health education programs and written guidelines for personal strategies to minimise harm from heatwaves.

 Heat health education programs mentioned in the literature include those for the general public, for vulnerable groups, and for health care providers, carers and volunteers.

 Guidelines for personal strategies to assist members of the public minimise the health effects of extreme heat for themselves and those around them can be found on web-sites, in leaflet form or in media releases.

 It is unlikely that passive dissemination of prevention guidelines will be effective if unaccompanied by active outreach to vulnerable groups, since these groups maybe unable to access or act upon this type of information.

70 71 3.14 Heatwave Response Plans

In response to past experience, or as a proactive response to a perceived threat, a number of cities and regions in the world have developed heat wave response plans (49, 126). Heatwave response plans provide details of actions that government and non-government agencies can take in the event of a heatwave being forecast, to reduce heat associated death and illness (26).

Meteorological data is used to predict the arrival of weather conditions defined as hazardous on the basis of an understanding of the relationship between temperature and health for that population (117).

Warnings are issued when thresholds of heat stress indicators are exceeded, and acute public health interventions initiated accordingly.

Heat-stress indicators used in various heatwave plans include air temperature (mean, maximum or minimum) (155, 156), combinations of air temperature and humidity such as Heat Index (39, 157), and complex indicators such as the synoptic system (158) in which impending air masses are predicted to be associated with increased mortality for a given population through the analysis of historic mortality and meteorological data, including temperature, humidity, air pressure, cloud cover and wind speed (159).

Most heatwave plans utilise a system of multi-stage warnings for an impending heatwave, allowing several days to activate preventive action. Terminology used for warnings varies, reflecting differences in public health infrastructure, and linguistic perceptions (160). For example, in the United States the maximum warning level, indicating a heatwave has arrived, is called a ‘Warning’ (126), while in

England this is called an ‘Emergency’ (156).

71 72 3.14.1 Effective heatwave response planning

Key components of heatwave response planning identified in the literature (49, 126, 160, 161) are outlined in

Box 13:

Box 13: Essential components of heatwave response planning identified in literature.

 Identification of a principle coordinating agency and other participating organisations.

 Preparations before the heatwave

 Identification and forecasting of a dangerous heatwave event.

 Assessment of the risk posed by the heatwave to the exposed population

 A consistent, standardised warning system that is activated and deactivated according weather conditions.

 The use of communication systems and public education programs.

 Public health interventions that target high-risk groups.

 Ongoing evaluation of plan effectiveness.

 Plan revision

Factors discussed in the literature as important for heatwave response planning to be effective include:

 public health and social infrastructure, and political will, to design and implement such programs (118),

 the availability of meteorological forecasts for the region of interest that are reliable and allow sufficient lead time for the institution of intervention activities before the heatwave arrives (1),

 the initiation of prevention measures before hot weather commences(1, 49, 118), in recognition of the fact that heatstroke is a condition that has a fast onset and is rapidly fatal(28), with prevention being facilitated by early identification, contact with, and observation of susceptible individuals (162),

72 73  the use of activation and deactivation thresholds that are based on an understanding of the relationship between meteorological variables and health outcomes for the population and region of interest (1),

 the use of straight-forward, unambiguous language to describe warnings and advice for avoiding heat associated illness (128),

 a consideration of the sensitivity and specificity of warning systems, since issuing unnecessary warnings or not issuing warnings when needed may have health consequences, and influence the willingness of the public to cooperate in the future (160),

 collaboration with key stakeholder groups, including funding bodies, participants in the heatwave response, and those affected by the heatwave, at plan development and review stages (160, 163),

 the involvement of multiple agencies in the implementation of interventions, including government, public health and social service workers, and emergency medical personnel (117), with agreement being reached regarding details of roles and responsibilities, geographic boundaries of the response plan, thresholds for actions, types of interventions, target groups, and communication protocols (26, 160),

 provision of adequate resources, capacity and knowledge for participating organisations and individuals (1),

 targeting of response measures to high risk groups, which will need to be preceded by gathering information about where high risk groups gather and reside (118),

 the collection of surveillance of data regarding weather, morbidity (hospital, ambulance use), mortality (medical examiner reports), electricity and water supply and demand, and response efforts, to allow evaluation and review of the heatwave plan (49),

 the incorporation of intervention effectiveness evaluation into the plan, allowing for corrections where necessary and the most efficient use of resources (160).

73 74 3.14.2 Public health interventions used in heatwave response plans

Public health interventions described in heatwave response plans vary widely, with some cities simply issuing warnings to the general public through the mass media (39), and others instituting a complex range of measures before and after heatwave events are forecast (149).

Interventions can be proactive, occurring before the heatwave occurs, or reactive once it has arrived.

Most heatwave response plans include a system of staged warnings before a predicted heatwave actually arrives, therefore allowing hours or days to institute proactive measures.

Essentially, public health interventions aim to reduce the impact of heatwaves by modifying the behavior of individuals or by modifying the environment in which they live (164). Informed by an understanding of the sudden onset of heat-related illness, of risk factors for illness and death during heatwaves, and of vulnerable groups, the main categories of interventions found in the literature are those that provide information about protective behaviors, facilitate access to cooler environments and drinking water, facilitate contact with vulnerable groups, and facilitate timely treatment for those with heat associated illnesses. More specifically, main types of public health intervention incorporated into heatwave response plans that are described in the literature are outlined in Box 14.

74 75

Box 14: Main types of public health interventions used in Heatwave Response Plans

 Provision of information to individuals and groups, regarding heatwave warnings and avoidance of heat associated illness, through the media, internet, leaflets, emails, telephone calls, direct contact.

 A telephone service that can provide information, advice and a referral service.

 Designated air-conditioned buildings are used as cooling shelters for the general public.

 Provision of transportation to cooling centers.

 Extension of the hours of operation of places where people can seek relief from the heat such as air-conditioned community centers and swimming pools.

 Ensuring extra emergency services and hospital staff are available.

 Suspension of utility shut-offs due to non-payment during heatwave alert period.

 Outreach activities, including home visits to registered at-risk individuals, checking of isolated neighbours using ‘buddy’ systems, and actively seeking out homeless individuals.

 Provision of sources of free drinking water.

Notable aspects of a number of heatwave plans operating in various cities and regions of the world, selected here for their large number of proactive and reactive interventions, are outlined below in Box

15. Interventions deployed as part of these heatwave plans are described in more detail in Tables 11 to

19.

75 76 Box 15: Notable aspects of a selection of heatwave response plans.

Location Description (Reference) Toronto (149) Characterized by its proactive nature, and also by the large number of agencies involved. Nearly 800 agencies are notified of a heat alert by Toronto Public Health, which plays a coordinating role. Agencies playing a major role are the Canadian Red Cross, libraries, homeless shelters, agencies responsible for community housing, city parks, home support, and the police and emergency medical services. The program provides extensive support and outreach for the homeless. Each agency has a clearly defined role to play, using existing resources and administrative structures.

Philadelphia(117, Characterised by its use of organisations that already perform similar tasks as program partners. 126, 131) For example, the telephone helpline is operated by the Philadelphia Corporation for the Ageing, using an existing service called ‘Senior Line’, but renamed Heatline during the summer months. An existing network of volunteer ‘Block captains’, who are elected by residents to help coordinate neighbourhood improvement programs, is utilized as a means of identifying and checking on isolated, high-risk individuals. Home visits to distressed individuals are conducted by staff seconded from the Health Department. Most interventions activated when a heat warning is called.

As part of this plan, the Department of Ageing, through a Seniors Well-Being Task Force Chicago (131, 157) encourages public and private organisations to identify elderly people who need monitoring and assistance. Organisations including church groups, Postal Services, and utility companies are asked to be on alert for elderly people showing signs of distress in hot weather. Also, people concerned about their health are encouraged to register for a 'well-being check' during a heat warning period. Registered individuals are automatically contacted by telephone before a heatwave arrives, to receive a recorded message with safety tips and information (131). This type of system has been criticized since it only provides a one-way form of communication, with no feedback as to whether the information is received or acted upon (165). During a heatwave, implementation of the plan is coordinated by the Chicago Fire Commissioner.

Rome(74, 117) At-risk individuals are encouraged to register for a tele-assistance scheme(117). This scheme operates during heat alerts, and provides a communication system between isolated individuals and various existing community services. Through the telephone system, which operates 24 hours a day, people can receive advice, food and medicine deliveries, regular check-in calls, and emergency assistance.

Catalonia (155) The Heatwave Plan implemented by this region of Spain is characterised by extensive proactive measures instituted at the commencement of the summer period before any alerts are called.

76 77 Proactive measures include dissemination of information, a telephone advisory and referral service, and a census of high-risk individuals. Primary Healthcare centres are asked to develop and maintain a database of high-risk individuals within their care, and these people are then visited at home, or seen at health centres, during a heatwave. A computer application has been developed for use by city councils to create a database containing details of high-risk individuals, and a catalogue of resources available in the municipality including cool shelters and means of transportation to these. (Available at http://www.gencat.net/interior/esc/docs/esc_planspc.htm#plantilles)

England (156) The Heatwave Plan for England includes a Heat-Health Watch system, based on Met Office forecasts, that triggers levels of response by the Department of Health and other public health authorities at national, regional and local levels. The plan is coordinated by the Department of Health, and includes proactive and reactive components as well as long-term planning to adapt to, and reduce the impact of climate change. Extra care for identified vulnerable individuals is described in care plans, and provided by social care services and the voluntary sector, utilising existing structures.

Shanghai, The Heat Health Warning System for Shanghai was a Showcase Project developed through the China (150) cooperation of several international agencies including the World Meteorological Organisation and the World Health Organisation, as well as Shanghai officials and the University of Delaware. The system first operated in 2001, and utilises a synoptic warning system and numerous proactive and reactive public health interventions.

Dayton and The cities of Dayton and Cincinnati are about 50 Km apart, and share a heat health warning Cincinnati, USA system triggered by similar weather thresholds. Health commissioners of both cities coordinate (166, 167) heat intervention activities of more than 150 ‘Heat Mitigation Partners’, and heat alerts are usually called in both cities at the same time. The two cities also share media outlets, through which alerts are announced and advice for reducing vulnerability to the heat is provided.

Milwaukee, An excessive heat conditions plan has been progressively refined since first being established USA (81, 168, 169) after a severe heatwave in 1995. One of very few heatwave plans to have been evaluated, a comparison of the health burden of heatwaves in 1995 and 1999 concluded that improved public health preparedness may have contributed to observed reductions in mortality and morbidity (81). The plan is characterised by extensive pre-summer preparations including education of the public and health professionals, and enrollment of at-risk individuals into registries to facilitate contact during a heat alert.

77 3.14.3 Heatwave Response Plans in Australia

Only two Australian States have any type of operational Heatwave Response Plan, as outlined in See

Table 20. Of these, the Queensland Heatwave Response Plan covering the area of South East

Queensland and including Brisbane, is the most comprehensive, and has been operating since 2004 (39,

170). In New South Wales, a Heatwave Pilot Project for the Central Coast Region was instituted in

September 2007 (37). Both responses have a two-tiered alert system but differ considerably in their scope and details, as described below and outlined in Table 21.

3.14.3.1 Queensland The Queensland response is part of a disaster plan in which Queensland Health coordinates a multi- agency response, as well as strategies for communicating advice to health care professionals, care staff and volunteers, and the public (39). A heatwave is defined using the heat stress indicator Heat Index

(equivalent to the Apparent Temperature but thought to be a less confusing term), which is a measure that incorporates temperature and humidity (171). The two tiered warning system consists of a ‘heat warning’ and ‘extreme heat warning’, with thresholds for warnings having been determined following analysis of Queensland’s experience of mortality and morbidity associated with heatwaves in 2001 and

2004 (172).

Public health interventions focus on preparedness for dealing with the health effects of an impending heatwave, and on providing the public with information about alleviating heat stress using media releases. When advised that weather conditions reaching the ‘heat warning’ threshold are forecast,

Queensland Health issues an alert to relevant Government agencies, triggering the activation of phases of readiness for an impending heatwave and associated health effects. When an ‘extreme heat warning’ is forecast, media statements are issued by Queensland Health and other agencies such as the 79 Ambulance Service, to provide the public with information regarding appropriate behavior to avoid heat-related illness.

3.15.4.2 New South Wales The intention of the NSW Central Coast Pilot Plan is to promote preventative action rather than simply respond to a disaster situation (173). The thresholds used to activate the plan were identified following a study of the relationship between climate and hospital admissions in different geographical locations of

NSW on days of extreme heat. At these thresholds, emergency hospital admissions were found to increase for people with certain underlying conditions, including mental and behavioral disorders, diseases of the nervous system, cardiac disease, chronic obstructive airway disease, diabetes and urolithiasis (174). Terms used in this plan also include an ‘Extreme event’, defined as maximum daytime temperature equal to, or greater than 37°C for an extended time in conjunction with bushfires and/or power failure

Upon activation of this Plan, the media will release information to the public, and the Division of

General Practice will be contacted. General Practitioners will be provided with information for their own use, and pamphlets to distribute to their patients. As yet, no other health care providers are involved in this pilot response (37).

79 80

Box 16: Main points - Heatwave Response Plans

 Heatwave response plans provide details of actions that government and non-government agencies can take in the event of a heatwave being forecast, in order to reduce heat-associated death and illness.

 A number of cities have developed Heatwave Response Plans that include warning and public health intervention components.

 Heatwave warning systems have been developed for cities using meteorological data to predict the likelihood of predetermined thresholds of heat-stress indicators being exceeded. These thresholds are based on an understanding of the relationship between weather and human health for the population and locality in question.

 Public health interventions utilised by Heatwave Response Plans around the world have a number of common elements, these having been based on an understanding of the sudden onset of heat-related illness, of risk factors for illness and death during heatwaves, and of the characteristics of vulnerable groups in populations.

 A number of commentators have made recommendations regarding important factors to include in the process of heatwave response planning.

 Only two Australian States have any type of operational Heatwave Response Plan: that in Queensland which covers the area of South East Queensland including Brisbane, and a pilot program operating for the Central Coast Region of NSW. Both responses have a two-tiered alert system but differ considerably in their scope and details.

 Research and pilot projects are currently underway in Victoria for the purpose of informing the development of a Statewide Heatwave Response Plan.

3.15 Long-term strategies for minimising harm from heatwaves.

Heatwave response plans are acute responses to heatwave events (150). It is recognized that long-term intervention strategies are also needed to effectively address the health impact of heatwaves, particularly in light of predicted climate change scenarios. Long-term interventions focus on building design, the reduction of urban heat islands and a range of other strategies.

80 81 3.15.1 Building design

A number of commentators have called for building regulations to include a maximum heat standard

(163, 175). For instance, Toronto Public Health is proposing the adoption of a Maximum Indoor

Temperature Threshold of 32°C to provide a threshold to aid assessment of indoor environments of vulnerable people, and initiation of evacuation procedures (165). It has been pointed out that while building codes commonly require that heating devices are available in rental or public residential properties, provision for cooling equipment is rare(132).

Innovative building design, such as the K2 public housing development in Melbourne, has been used to minimise the need for energy driven cooling devices by allowing ventilation, maximizing shade and minimising heat gain (176).

3.15.2 Reduction of urban heat islands

The City of Philadelphia has operated a program through the Energy Coordinating Agency called the

‘Cool Homes Program’, which has provided low-income elderly residents with a variety of non- mechanical cooling measures including applying a white acrylic, light reflecting, elastomeric roof coating, and roof insulation.

Parallel goals of the program are to educate residents about strategies for keeping cool during the summer, referral to other agencies if needed, and the creation of a social network for participants (131).

Many homes in Philadelphia have flat, bitumen covered roofs, and are therefore ideally suited to this type of treatment (177).

The United States Heat Island Reduction Initiative assists cities to adopt heat island reduction strategies that include identifying ‘hotspots’ using satellite technology, installing ‘cool roofs’, planting trees and vegetation, and using cool paving materials(130). Cool roofs are those made of reflective materials,

81 82 painted white, or installed with a roof-top garden. Paving material recommended are those that are light-coloured and therefore reflective, or porous and cool when wet.

A number of cities in Europe, Toronto and Tokyo encourage the use of ‘green roofs’(175). These are roofs with vegetation on them, which reduces the amount of heat radiated from buildings. Tokyo also has used vegetation and design to create ‘ventilation corridors’ that allow cool air from surrounding areas to cool the city (175).

3.15.3 Other strategies

Other strategies discussed in the literature include:

 Use of renewable energy for cooling purposes, thereby reducing the use of fossil fuels and concomitant release of greenhouse gases.

 Reduction of the number of motor vehicles entering city areas, since these add heat to the urban environment and pollute the air with heat-trapping particulate matter. For instance, Transport for London has introduced a ‘Congestion Charge’ to discourage motorists from driving into London (178).

 Promotion of community programs to raise the fitness of the population, including the elderly, since improved fitness is associated with greater cardiac reserve, and a more efficient thermoregulatory response (117).

Box 17: Main points - Long-term harm minimisation strategies

 Long term harm minimisation strategies include improved building design, the reduction of urban heat islands, reduction of green house gas production, and improved fitness of the population.

 Strategies that have been reported for reducing the urban heat island effect include applying light reflecting roof paint, improving house insulation, planting trees, using light coloured building materials, installing roof-top gardens, and creating ventilation corridors.

82 83 3.16 Programs that indirectly address risk factors for heat associated death and illness.

Being elderly (59), living alone (20, 108), not leaving home each day (112), not having social contacts (109), poor housing conditions (109), homelessness (126), and lower socioeconomic status (58, 108, 109) are known to be strongly associated with an increased risk of dying during a heatwave, while participating in social activities (20, 108, 112), having a working air conditioner (108, 112), having access to transport (20), and having a pet have been found to be protective (20, 108). Therefore, programs that address the issues of social isolation, poor housing conditions and economic deprivation of the elderly may contribute to minimising harm during heatwaves, without being specifically focused on this issue.

Examples of programs that aim to reduce social isolation are discussed below:

Red Cross ‘Telecross’ Program

Telecross is a national program operated by the Red Cross that provides a telephone call once each day, free of charge, to eligible clients. The program is available to the elderly, those with a disability and medically dependent people who lack social support or who live alone. Its purpose is to check each day that clients are safe and well, while also helping to alleviate their social isolation. Telephone calls are made by trained volunteers who adhere to a strict protocol to initiate follow-up procedures, such as contacting next of kin or General Practitioner, if calls are not answered. In Victoria, this service is funded through public donations, but receives funding through Home and Community Care (HACC) elsewhere around Australia (179).

Preliminary discussions are currently underway to extend the role of Telecross to provide precaution warnings in extreme weather conditions, such as heat waves, dust storms and fires, and seasonal health alerts including reminders to have flu vaccinations. Consideration is also being given to broadening the service to include reminders to take medications (180).

83 84

In NSW, Telecross has been commissioned by the Department of Housing to provide a daily telephone call to elderly public housing tenants. This service, named Housing NSW Care Call, will commence in

July 2008, and will target tenants who live alone and are aged over 80 years (or over 75 years if they are very frail), or who are aged over 55 years in the case of Aboriginal tenants. The program is free and voluntary, and will eventually also include a referral service to other community services (181).

Box 18: Main points - Strategies that indirectly address risk factors for harm during heatwaves.

 Programs that address the issues of social isolation, poor housing conditions and economic deprivation of the elderly may contribute to minimising harm during heatwaves, without being specifically focused on this issue.

 Examples of such programs include the Red Cross ‘TeleCross Program’, and the Housing NSW Care Call program instituted by the New South Wales Department of Housing.

3.17 Evaluation of harm minimisation strategies

Key Question 8: How effective are these harm minimisation strategies?

Little is available in the published literature regarding formal evaluation of the effectiveness of heatwave plans or of specific interventions. Difficulties associated with evaluating heatwave response plan effectiveness include the infrequent and variable nature of heatwave events, the varying impact of

84 85 heatwaves on different populations, the uncertainty regarding the forward displacement of deaths, the time taken to obtain accurate mortality data, and the varying methods used to define and quantify heatwaves and their associated health burden (1, 31, 150, 182).

Studies of successive heatwaves in the cities of Milwaukee (81), Chicago (129), Shanghai (183)and in

France (184), have compared the health impacts of heatwaves with similar meteorological characteristics occurring several years apart, with the second heatwave occurring subsequent to the institution of improved public health heatwave response measures. In all cases, the health impact, as indicated by mortality (81, 129, 183, 184) and morbidity (81), was found to be reduced following improved public health preparedness. However it is not possible to robustly attribute reductions in mortality and morbidity to public health interventions alone since population vulnerability to extreme hot weather is influenced by a variety of other factors including demographic and socioeconomic population characteristics, housing conditions, access to air-conditioning, and urban design, all of which can change over time (87, 183). For instance, it was concluded that the increased use of air-conditioners, larger living spaces and more green spaces in urban areas of Shanghai had contributed to the reduced health impact of a heatwave in that city in 2003, as well as increased population heat health awareness and the use of a heatwave warning system (183). A comparison of the health burden associated with heatwaves in St.Louis, USA, in 1980 and 1995, found that despite the institution of a heatwave response plan, population vulnerability to death during heatwaves had increased and this was most likely due to an ageing population, rising rates of poverty, and reduced social security support (87).

The Heat Watch/Warning system operating in Philadelphia was evaluation for lives saved and economic cost. It was concluded that during the period 1995 to1998 the system saved 117 lives, with

2.6 lives being saved for each heatwave warning day and following three days, and that the costs of operating the system were lower than the value of lives saved. (182). This cost-benefit analysis assumed no forward displacement of mortality, and did not include the benefit of morbidity reduction.

85 86 Two surveys have been located in the literature that have been used to evaluate the effectiveness of heat warnings (128, 167). A telephone survey of people aged over 65 years living in four North American cities was used to evaluate the effectiveness of heat warnings by assessing awareness and response of target populations (167). It was found that while most respondents were aware of heatwave warnings having been made, fewer recalled the accompanying advice given, and only about half modified their behavior accordingly. This study also found that most people had learned of heat warnings through the television with very few reporting the internet as their major source of information; more than half the respondents believed that heat was not dangerous for them; one third of people with air conditioners cited economic considerations as determining their air conditioner use; most people who used fans did so in closed rooms contrary to publicised advice; and a number of people indicated confusion about different warning levels and concurrent warnings for air-pollution. A questionnaire distributed to a cross-section of residents of Phoenix, Arizona, similarly found that while most respondents were aware of days when heat warnings had been issued, less than half did anything different on those days as a result. Furthermore, those individuals most likely to change their behavior on heat warning days were those who perceived the greatest risk from heatwaves (128).

Limited information regarding the evaluation of individual public health measures has been located in the published literature, in various Government reports, and through personal communications.

Pertinent findings from Milwaukee (81, 169), Toronto (149) and Queensland (172) are summarised below:

Milwaukee

 The 24-hour helpline established during heat alerts typically receives a peak number of calls in

the evening, perhaps reflecting the health impact associated with elevated night-time

86 87 temperatures. The authors suggest that it may be important to focus public health prevention

efforts on night-time heat (81).

 Few of the agencies participating in the heat response plan operate 24-hours a day, slowing

communication with and response of these agencies (169).

 Efforts to distribute air-conditioners to high-risk individuals have been hampered by the time

taken to screen and process a large number of requests, client inability to install units,

inadequate wiring in homes, and transient clients leaving air-conditioners behind (169).

Toronto

 It has been found that cooling centers were not well utilized by at-risk people. In summer 2006,

most people who visited a cooling center did so because they were in the building or happened

to be passing by. The average length of stay was 15 minutes. This is despite the location of

cooling centers being extensively publicised, and transportation to cooling centers being

facilitated. It is suggested that a reluctance to leave homes or immediate neighbourhood could

be addressed by offering door-to-door transport, and providing cool shelters in local libraries

and community centres that are familiar to potential users (149).

 Extra short-term beds made available in Homes for the Aged during heat alerts in 2006 were not

used because potential recipients of this service refused to leave their homes (149).

 Extending the opening hours of drop-in centres for homeless individuals throughout summer

has been a successful intervention, providing a cool shelter during heat alerts, as well as a meal

and an opportunity for individuals to access other services (149).

 A survey assessing the outreach efforts in summer 2007 of 450 participating community

agencies is due for completion in 2008 (149).

87 88 Queensland

A review of the Queensland Heatwave Response Plan is due for completion mid-2008 (170). A number of observations have been made over the past three years (172):

 It has been a challenge to persuade shopping centre management to participate with a program

advising elderly people to go to shopping centers to keep cool.

 It has been difficult to persuade the elderly not to lock their homes up during a heatwave, with

many not understanding that this makes it hotter inside after a while.

 Ambulance air conditioners have failed during prolonged use during heatwaves. It has been

useful to have stockpiles of cold drinks for paramedics to access at hospitals.

 Despite the Department of Education intentions for children to be sent home when temperatures

reach a certain threshold, this has not been possible to implement since there may be no one at

home to look after children at home during the day.

The importance of including evaluation criteria in heatwave response planning, implementation and review has been emphasised by a number of commentators (1, 159, 160). The development of standardised evaluation guidelines has been suggested to facilitate comparable evaluation of the increasing number of heatwave plans in operation (1, 117, 159). Suggested evaluation criteria have been described in the literature and include analysis of need; a description of system objectives, components and operation, including a flow diagram illustrating all system steps; an analysis of resources and costs; and evaluation of the system as a whole, as well as individual measures, for simplicity, acceptability, sensitivity, specificity, timeliness and effectiveness (1, 117).

88 89 Box 19: Main points - Evaluation of strategies to minimise harm during heatwaves.

 There has been limited formal evaluation of the effectiveness of heatwave response plans or of individual intervention measures.

 Four studies of successive heatwaves in the same location have reported a reduced heath impact of heatwaves subsequent to the institution of public health preparedness and response programs. However, while these measures may have contributed to the observed reductions in mortality, population vulnerability is also influenced by a number of other factors.

 Surveys of public awareness and response to heatwave warnings have found that while most respondents were aware when heat warnings were issued, less than half modified their behavior as recommended. Perceptions of risk strongly influenced the likelihood of individuals following heat protection advice.

 Reports of health agencies have provided some insight into the effectiveness of individual intervention measures, including peak access times for telephone help-lines, access to participating agencies, distribution of air-conditioners, utilization of cooling shelters, drop-in centres for homeless individuals, use of shopping centres as cool spaces, and closing of schools when temperatures reach threshold levels.

 It has been recommended that standardised evaluation guidelines be developed to facilitate comparable evaluation of the increasing number of heatwave plans in operation.

89 90 4. Summary & Conclusion The purpose of this literature review has been to examine the current knowledge of the health effects of heatwaves, and of heatwave risk reduction strategies, in order to inform the development of effective harm minimisation policies and strategies for use in Victoria. A number of key questions were used to guide the review, and a summary of findings that address these questions is presented in Box 18.

Box 20: Summary of responses to key questions guiding the literature review

1. How should an episode of ‘extreme hot weather’ be defined?

An episode of extreme hot weather, or heatwave, is difficult to define since the response to extreme hot weather varies between populations and within populations over time, with vulnerability influenced by opportunity for acclimatisation as well as population and heatwave characteristics. The basic components of a heatwave definition include the event threshold and duration observed to be associated with increased morbidity and mortality of the population in question; lack of a standard definition makes comparison of individual heatwave events difficult.

2. Are heatwaves expected to occur more frequently in the future?

The fourth report from the Intergovernmental Panel on Climate Change has concluded that global warming is undoubtedly occurring, and this is likely to be associated with an increased frequency and severity of heatwaves in the future. It is predicted that the increased frequency of heatwaves will result in an increase in heat-associated deaths in Australian cities, including Melbourne.

3. What has been the health burden from heat waves in Australia and internationally?

Heatwaves have been associated with large short-term increases in deaths in cities and regions of temperate zones of the Northern hemisphere. It is estimated that in 2003, up to 70,000 additional deaths occurred over the summer months in Western Europe as a consequence of severe heatwaves. In Australia, the health burden of heatwaves has been less extensively documented, however it is estimated that more than 4,000 deaths have occurred over the past 100 years as a consequence of heatwaves, twice the number caused by cyclones or floods over the same period of time. The health burden of heatwaves predominantly affects the elderly, particularly those who are already ill and socially isolated. Deaths are reported to occur quickly, often within the first one or two days of a heatwave, and are most often due to exacerbation of pre-existing illnesses. Those who develop heat stroke, have a

90 91 poor short term and long term prognosis. It is considered likely that air pollution has a role to play in accentuating the harmful health effects of heatwaves.

4. What factors influence the risk of death and illness occurring in association with an episode of extreme hot weather?

Characteristics of heatwaves, exposed populations and the environment in which they live influence the risk of deaths and illness occurring during heatwaves. Heatwaves of several days duration, with high average daily temperatures, and occurring early in the summer season are the most harmful. Characteristics of individuals that put them at greater risk of harm due to heatwaves are being bed-ridden, socially isolated, dependent on others for care, elderly, poor, and chronically ill, particularly due to cardiovascular, respiratory, neurological or psychiatric disorders. Living in a city, and in older housing also increases risk. Having a working air-conditioner, visiting cooler environments, and participating in social activities have been identified as the factors most strongly protective against death during heatwaves. Fans are not considered effective when temperatures and humidity are high, and may be harmful if used in enclosed, hot environments.

5. Which population groups are at most risk of harm from extreme hot weather?

Vulnerability to extreme hot weather will be increased in individuals with compromised physiological responses to excessive heat, those who have reduced ability to modify their behavior in order to care for themselves, and those who have limited access to resources.

Population groups most vulnerable to harm during heatwaves are the elderly, the very young, those taking certain prescribed medications, people with chronic illnesses, the homeless, people who are socially isolated, those who are economically deprived, and those who abuse alcohol or illicit drugs.

6. Why are the elderly particularly vulnerable to extreme hot weather?

Age-related changes can diminish the effectiveness of thermoregulatory responses, as well as thirst and renal mechanisms for regulation of body fluid balance.

Chronic illnesses known to increase the risk of death during heatwaves are more prevalent in the elderly. These chronic health problems in conjunction with medications used in their treatment may increase vulnerability to hot weather through compromising thermoregulation, mobility, awareness of a hot environment,

91 92 or the ability to adopt protective behaviors.

A large proportion of elderly people are socially isolated, with this also contributing to their increased vulnerability to harm during hot weather.

7. What strategies have been adopted to reduce harm to the elderly due to extreme hot weather?

Strategies adopted to reduce harm during heatwaves include dissemination of guidelines for behavior during hot weather, public education programs, and the development of heatwave response plans. A number of heatwave response plans have been developed for cities and regions in the Northern hemisphere. These generally include warning and public health intervention components. Warning criteria are based on an understanding of the relationship between heat stress indicators and health for the population in question. Public health interventions vary and ideally include proactive and reactive components informed by an understanding of the nature of heat-related illness, of the risk factors for illness and death during heatwaves, and of vulnerable groups.

8. How effective are these harm minimisation strategies?

Few studies have formally evaluated the effectiveness of heatwave response plans as a whole or of individual interventions; however a number of studies have reported a reduced heath impact of heatwaves subsequent to the institution of public health preparedness and response programs.

Numerous epidemiological studies, mostly of populations in North America, Europe and the United

Kingdom, have shown that the people most likely to die or be admitted to hospital during extreme hot weather are the elderly. Those who die are more likely to live alone, to be socially isolated, economically disadvantaged, and to have co-existing debilitating diseases, reflecting a complex interaction of physiological, social, behavioral and pathological factors that combine to increase the vulnerability this population group to heat associated morbidity and mortality.

Deaths occurring during heatwaves are not always due to hyperthermia but are often due to an exacerbation of underlying cardiovascular, respiratory or other disease. Furthermore, only a small proportion of these deaths appear to be due to the forward advancement of deaths expected to occur in

92 93 the near future. Heatwaves having the greatest impact on health are those occurring early in the summer season, particularly in cities and locations where populations have had little experience of sustained periods of hot weather; several days of extreme temperatures, with high night-time temperatures are the most lethal. The death toll from a heatwave appears early in the event, with many people succumbing quickly before they are able to reach medical help, or be noticed by others. On the other hand, there is evidence that having a working air conditioner in the home, spending time in cooler locations during a heatwave, and participating in social activities reduces the risk of death during a heatwave.

These findings have implications for public health policy, and for the development of a Statewide

Health Response Plan. In particular, the rapid onset of heat-associated illness underlies need for planning before heatwave season, early prevention strategies, and prior identification of the most vulnerable groups. The health impact of high night-time temperatures suggests that the availability of public health measures during the night as well as the daytime, such as a telephone help and advisory line, out-reach activities, and access to cool environments, are important. Long-term measures are also needed to address the urban heat island effect, to enhance cooling of cities during the night.

A number of research gaps have been identified in the literature. There has been only limited evaluation of the effectiveness of heat wave response plans and of individual response interventions, despite the large number of heatwave response plans described (1, 160). Evaluation of these measures in terms of lives saved, public perception, knowledge and behavior, as well as reach, ease of operation, cost-effectiveness and quality are necessary for determining the most effective ways of reducing heat- associated illness and death, with the most efficient use of resources.

93 94 While evidence of risk factors for harm during heatwaves helps to inform the development of appropriate interventions, there is little in the literature to explain more precise mechanisms connecting risk factors with outcomes (132). For instance social isolation may be associated with deaths during heatwaves because of the characteristics of people who live alone, or because such people lack someone to notice they are ill. There is little information regarding minimum time to be spent in a cooler environment for protection from death during a heatwave, or the appropriate use of some interventions, including the use of fans, drinking extra water, taking extra showers and baths, all of which could be hazardous in some situations for some people.

Information regarding the effects of extreme heat on the morbidity of populations is also lacking.

Finally it important to note that most evidence of the relationship between extreme heat and human health is derived from studies of populations living in Northern hemisphere cities. Few studies are available regarding Australian populations.

It is likely that as a consequence of global climate change, episodes of extreme hot weather will become more frequent and more intense in the future. There is considerable evidence that heatwaves have an adverse impact on the health of those least able to care for themselves, particularly the elderly.

An appreciation of the body of literature describing the current knowledge of risk factors and risk reduction strategies is important to facilitate adaptation to this scenario through the development of effective responses to heatwaves.

94 95 5. Glossary Adaptation: Adaptation refers to measures implemented in response to actual or expected environmental hazards, in this case heatwaves, for the purpose of reducing their health impact (11).

Elderly: While there is no international standard numerical criterion for the age at which a person becomes ‘elderly’, most developed countries accept this to be the arbitrary value of 65 years(12). For the purpose of this literature review, the term ‘elderly’ will refer to people who are aged 65 years or over.

Excess deaths: regarding heatwaves, refers to the difference between the number of the observed deaths and the number of expected deaths, based on death rates for the same geographical area over an appropriate control period during which no heatwave or epidemic occurred (185).

Greenhouse gases: Greenhouse gases are gases that trap heat in the atmosphere by absorbing some of the radiant heat emitted from the earth’s surface (186). The main greenhouse gases produced as a consequence of human activity are carbon dioxide, methane and nitrous oxide (187).

Heat health warning system: A harm minimisation strategy that uses “meteorological forecasts to initiate acute public health interventions designed to reduce heat-related impacts on human health during atypically hot weather”(1).

Heatwave: A variety of definitions of this term are found in the literature. For the purpose of this discussion, the term ‘heatwave’ will be used to mean “a prolonged period of excessive heat”(14).

Hyperthermia: An abnormally high core body temperature caused by an inability of the body’s thermoregulatory mechanisms to adequately dissipate heat (19). This may occur when thermoregulation is impaired by drugs or disease, or overwhelmed by excessive environmental heat or excessive metabolic heat production (24, 27)

Public health interventions: Organised activities intended to promote or protect health or prevent ill health in communities or populations, and are often directed at determinants of health (or ill health).

95 96 Mitigation: This term refers to interventions that are focused on the reduction of the severity of a particular hazard, in this instance extreme hot weather.

Percentile: The percentile is the percentage of values that fall at or below that score(188).

Public health: An “organised response by society to protect and promote health and to prevent illness, injury and disability”(189).

Risk: The likelihood that an adverse outcome will occur in a person, or group of people, in a certain timeframe, as a consequence of being exposed to a particular hazard (in this case, extreme hot weather)(11).

Risk factor: A behavior, environmental exposure, social circumstance, or inherited characteristic that will increase the probability of poor health occurring (11, 190).

Time-series: A set of observations collected sequentially over time (191).

Time-series analysis: Refers to the analysis of a set of time-series data. With regard to the investigation of heatwaves and health, time-series mortality and temperature data have been collected and analysed for the purpose of examining the relationship between these variables in single or multiple geographic locations over extended periods of time (4).

Urban heat island: This term refers to urban areas where air temperatures are higher than for surrounding rural areas (130). Urban heat islands arise because in addition to extra heat generation, cities retain more heat at night because they have tall buildings that block cooling breezes, lack vegetation, and are constructed with heat-absorbing building materials (80).

96 97 6. Appendix: Tables 1 - 21

Table 1: Definitions of 'heat-related death'

Reference Definition (18) “a death in which exposure to high ambient temperature either caused the death or significantly contributed to it”

(31) Death considered to be heat related “if there was no history of trauma or evidence of fatal injury and the case met at least one of several criteria: measured body temperature had to be 40.6°C or higher immediately before or after deaths, evidence of high environmental temperature at scene of death, --- person last seen alive during heatwave”

(20) “heat listed as immediate, underlying or contributing cause of death”

(32) “exposure to hot weather, a body temperature of 40.6°C or higher, and an absence of other causes of hyperthermia”

(19) "a death in which exposure to high ambient temperatures either caused the death or contributed to it substantially, the decedent had a body temperature at the time of collapse >105°F (>40.6°C), the decedent had a history of exposure to high ambient temperature, and other causes of hyperthermia could reasonably be excluded."

97 98 Table 2: Definitions of the term ‘Heatwave’ Organisation / Author and Date Definition (Reference) Australian Bureau of Meteorology (14) "a prolonged period of excessive heat”

Intergovernmental Panel on Climate "Episode of several consecutive high temperature days/nights" Change (6)

American Red Cross (34) A “prolonged period of excessive heat and humidity”

Basu & Samet, 2002 (4) “an event that provides a well-defined period of extreme temperature with a high risk of adverse health effects and mortality”

Royal Dutch Meteorological Institute (5) At least 5 days with a maximum temperature of 25°C or above, including at least 3 ‘tropical days’ with a maximum temperature of 30°C

Hajat, 2002 (35) "individual hot day periods of five days or longer identified using ---the 97th centile of average temperatures (calculated over a twenty one year period) as a threshold”.

NSW Central Coast Pilot Heatwave Maximum temperature greater than 35°C for more than two days. Program (37)

Centres for Disease Control and “≥3 consecutive days of air temperatures ≥90°F (32.2°C)” Prevention(192)

Kysely, 2002 (193). A period of at least three days during which the daily maximum temperature is ≥30°C. The heatwave persists as long the average maximum temperature of the whole period remains above 30°C and the daily maximum temperature never drops below 25°C.

Queensland Bureau of Meteorology (39) Heatwave: when the Heat Index is expected to reach or exceed 34 on two or more consecutive days in Brisbane. Extreme Heatwave: when the Heat Index is expected to reach or exceed 38 on one or more of the days identified as being part of a heatwave.

Gaffen & Ross, 1998 (38) "runs of three or four consecutive days with daily average Apparent Temperatures (AT) exceeding the 85th percentile value (above which mortality increases sharply)".

Nitschke, 2007(79) A period in which the daily maximum temperature was ≥35°C for 3 or more consecutive days

Bouchama & Knochel, 2002 (27) “three or more consecutive days during which the air temperature is >32.2°C”

Mechellozzi, 2005 (58) "days with Tappmax (index of temperature/humidity) above 90th annual percentile, and for the first day an increase of 2°C compared with the previous day”.

98 99 Table 3: Examples of different methods used to estimate 'excess deaths'. Heatwave Reference Baseline estimate used to calculate ‘excess deaths’ event Average mortality for same time periods in 2002-2003 (59) France, 2003

(58) Italy, 2003 Smoothed daily average mortality for 1995-2000 for three cities.

(73) Spain, 2003 Time-series analysis of 50 cities for 1996-2002, and for 1990-2002

(54) England and Average of deaths for same months of 1998-2002 Wales, 2003

(5) Netherlands, 2003 Linear regression analysis of weekly temperature and mortality curves, using average data for previous 30 years

(53) Portugal, 2003 Average of deaths occurring over three periods in July 2003 that didn't include heatwave days.

(76) Switzerland, 2003 Average deaths occurring 1990-2002

99 100

Table 4: Descriptive studies of mortality associated with specific heatwave events. Exposure: Outcome: Baseline measurement used to Location - Heatwave event Mortality (all cause) Other Observations calculate excess mortality. (reference) attributed to heatwave St. Louis and Kansas City - Deaths increased by 57% and Rates of heatstroke higher for those age ≥65 years Mortality compared with 1980 (82) 64% respectively corresponding period of previous two years.

New York City - June 1984 35% increased mortality rate Excess most pronounced for persons aged ≥75 years, Comparison with average (57) for women, and for people living at home. mortality rate of previous four weeks.

Athens - 21-31 July, 1987 Approximately 2000 heat- Death most common in the elderly, mortality highest (56) related deaths in first 2 days of heatwave.

5 Counties of north eastern 26% increase in total All Counties showed an increased mortality due to Mortality during a non-heatwave United States – heatwave of mortality. cardiovascular disease, especially Philadelphia (98% period in June 1993. 6-16 July, 1993 (55) increase). Risk of dying from cardiovascular disease greatest for those ≥65 years, for both sexes, all races.

Chicago - July 14-20, 1995 739 excess deaths (31% Heat-related deaths more common in men, and those Regression analysis for months of (31) increase) aged ≥65 years. Mortality peaked 2 days after peak June to September for 16 years, 514 heat-related deaths temperatures. Heat-related deaths < than excess 1979-1994. deaths.

England, Wales and Greater 619 excess deaths (8.9% Excess mortality occurred in all age groups, 31 day moving average London - 30 July-3 August, increase). For Greater London especially for women, and for respiratory and temperatures for 1995 (15 days on 1995 (52) area mortality increased by cerebrovascular disease as cause of death. Night- either side of the index day). 16.1%. time temperatures higher in London. Role for air- pollution in excess deaths.

England and Wales - 4-13 2139 excess deaths (16% Excess deaths especially for those ≥75 years, living Average of deaths for same August, 2003(54) increase). For Greater London in London area. Air-pollution contributed to deaths. months of 1998-2002. 40% increase in mortality. London experienced high night-time temperatures.

100 101 Table 4 continued: Descriptive studies of mortality associated with specific heatwave events.

Exposure: Outcome: Baseline measurement used to Location - Heatwave event Mortality (all cause) Other Observations calculate excess mortality. (reference) attributed to heatwave France - 2-15 August, 2003 14,800 excess deaths (60% Women ≥75 years old most affected. In elderly, Average mortality rate for 2000- (59) increase) increased deaths mainly due to heat-related disease, 2003 cardiovascular, respiratory and nervous system disorders. Lag times of 1-3 days observed. Heatwave not followed by deficit in mortality.

13 cities in France , 1-15 All cities had increased Peak deaths 1-3 days after start of heatwave. Average deaths during summer August, 2003 (62) mortality, with rate increasing 2002-2003. from 4%-142%.

Netherlands, 31 July-13 500 excess deaths Mortality increased mainly for elderly, especially Linear regression analysis of August, 2003. (5) those in nursing homes, and also 40-59 age group. weekly temperature and mortality Few deaths directly attributed to excessive heat. curves, using average data for previous 30 years

Portugal- 30 July-15 August, 1953 excess deaths (37.8% Excess deaths mainly in those ≥75 years, and for Average of deaths occurring over 2003. (53) more than expected) women. Especially due to heat-related disease, three periods in July 2003 that cerebrovascular disease, ischaemic heart disease, didn't include heatwave days. heart failure, respiratory disease, neoplasms.

Four Italian cities - Increased mortality: Rome Excess mortality greatest in those ≥75 years, and in Smoothed daily average mortality Heatwaves during summer of 19%, Milan 23%, Turin 33%, females. Especially for deaths due to disease of of Rome, Milan, Bologna for 2003 (58) Bologna 14% central nervous system, circulatory and respiratory 1995-2002, and Turin 1998-2002. disease, metabolic/endocrine, psychiatric illness. Peak mortality 1-2 days after start of heatwave. Highest excess mortality in north-west Italy.

21 Italian regional capitals- 22% overall increased Excess mortality mainly in those ≥75years (22% Mortality data recorded for same summer weather 2003(60) mortality in people aged ≥75 increase). Highest excess mortality in north-west cities during the summer months years. cities. Peak mortality up to 4 days after onset of high in 2002 temperatures.

Southern England – 33% increased deaths people For those ≥ 75, a disproportionate increase in deaths Average mortality by place of heatwave 4-13 August, aged ≥75 years. occurred in hospitals and nursing homes. death for 1998-2002. 2003(61)

101 102 Table 5: Time-Series Analyses of Mortality-Temperature Relationship Study Population Exposure Outcome Key Findings (Author, Date) 50 provincial capitals, Daily temperature, Excess deaths 15% increase in deaths during summer 2003, spatial distribution of excess Spain (73) summer months, 2003 deaths inconsistent across 50 cities. Excess deaths only in those aged 75 years and older (especially 85+ years).

Rome, Italy (74) Daily temperature, Excess deaths 23% increase in mortality compared with baseline. 29% increase in deaths apparent temperature, persons aged 75-84, 45% increase deaths aged 85+ years. 22% increase in summer months, 2003 out-of-hospital deaths. 12-17% increase in deaths of person living in medium/low – low socioeconomic status. Rome had a heat-health warning system operational at the time of the heat wave which may have been protective for some persons. This system has been upgraded post 2003 heat events.

9 largest cities in France Daily temperature, Relative risk of The relative risk of mortality varied across France from 1.16 to 5.00 (Paris). (64) summer months, 2003 mortality, excess deaths. There was little effect of ‘harvesting’ therefore many deaths may have been preventable.

Switzerland (76) Daily temperature, Excess deaths 7% increase in mortality during 2003 heat wave. Excess mortality limited to humidity, dew point, 2003. areas north of the Alps, and more pronounced in the elderly (80+years). Slightly stronger effect noted for females than males.

12 US cities (66) Daily temperature and Deaths due to Areas with larger annual temperature ranges had an increased heat stress humidity, 1986-1993 respiratory and response. MI deaths on hot days were twice those on cold days, CVD deaths cardiovascular disease. were five times less on hot days than cold days. Small harvesting effects noted no clear pattern for effects of humidity.

12 US cities(67) Daily temperature and Daily deaths In cold (northern) cities, high temperatures associated with excess mortality, humidity, 1986-1993 no noted lag effects. In hot (southern) cities, the effects of increased temperature were smaller and varied with use of air-conditioning. No clear humidity effects.

11 eastern US cities (65) Hourly temperature, 1973- Relative risk of Strong association with latitude and temperature/mortality relationship with 1994. mortality. increased effects of heat noted in the more northern cities. Air-conditioning in homes used as indicator of socioeconomic status, and predictor of weather related mortality

102 103 Table 5 continued: Time-Series Analyses of Mortality-Temperature Relationship

Study Population Exposure Outcome Results (Reference) Warm and cold regions Daily temperature, 1988- Mortality Selective population persons aged 65-74 years. Warmer areas of Europe had in Europe (69) 1992 higher temperature thresholds for hot weather than colder areas. However, warmer areas did not have significantly higher related mortality rates than cold regions when the thresholds were exceeded.

Sofia and London)(68) Two day, and two week All cause mortality Temperature –mortality relationships exist in both locations. The inflection average temperatures, points and slope varied between the two locations. Stronger heat effects noted 1993-1996 in Sofia may be related to harvesting effects.

7 US cities (70) Daily mean apparent Mortality Heat related deaths were five times more likely to occur outside of hospital, temperature, 1986-1993. there were also higher mortality rates for African Americans, less educated, heat effects varied with age (elderly 65+ years increased mortality) but no gender effects noted.

Valencia, Spain(77) Mean temperature, 1991- Daily mortality Threshold temperature of 24o C during summer months for each degree 1993 above this threshold there is a 1-4% increase in mortality. No significant relationship between heat and CVD and carcinoma, a lag of 7-14 days associated with respiratory deaths. No significant relationship was found between humidity and mortality.

Vienna, Austria (75) Average temperatures for Relative risk of Heat waves were associated with a 13% increase in mortality; this effect was May - September, 1970- mortality, excess stronger in females than in males, and persons older than 65 years. There was 2004. mortality. no discernable harvesting effect.

Barcelona, Spain (95) Daily temperature and Total mortality, Mortality increased during periods of unusual weather. In summer, this humidity, 1985-1989 mortality for those increased daily mortality by 1.7% (2% persons 65+ years). CVD mortality >65years, rose by 4.2% in summer and respiratory mortality by 13.2%. Only periods cardiovascular and with increased temperature and humidity were associated with increased respiratory mortality. mortality.

103 104 Table 5 continued: Time-Series Analyses of Mortality-Temperature Relationship

Study Population Exposure Outcome Results (Reference) Elderly in 5 cities in Heat-stress days(heat Mortality Apparent temperature days >32oC resulted in increased mortality. The effects Southern Ontario, index exceeding 32°C), were stronger in the elderly (64+ years). Cities with the highest heat related Canada (71) 1980-1996 mortality had high levels of urbanization, high costs of living.

28 metropolitan areas of High Apparent Annual excess mortality Heat related mortality declined in the US between 1960’s and 1990’s. The US (72) temperature, 1964-1998. effects were noticed first in the hotter southern states and spread northward during the 1990’s. This was attributed to technological, behavioral and biophysical adaptations. Suggesting that humans can adapt to predicted changes in climate due to global warming.

People aged ≥ 55 in Daily temperature, 1971- Daily mortality Three geographically diverse locations demonstrated a reduction in heat North Carolina, South 1997. related mortality over time despite increased average summer temperatures in Finland and Southeast 2 of the 3 regions. Reduction in heat related mortality was attributed to England (63) increasing prosperity and air conditioning in these regions.

Greater London(35) High temperatures, 1976- Daily mortality A threshold of temperature of 21.5oC was identified for London. A 3.3% 1996. increase in mortality occurred for every degree above this value. The heat wave in 1976 had the most profound effect on heat related deaths during the study period. Seasonal timing indicates that heat events in the earlier part of the year have a greater impact than those occurring later in the season. Heat episodes of the longest duration and amplitude have the greatest mortality impacts.

London, Budapest and Daily temperature and All cause mortality Although heat wave effects are noted in time-series analysis their effects are Milan (48) humidity, 1970-2003 small when compared with the overall effects of summertime temperatures. Reducing the burden of heat related mortality requires a broader approach than addressing heat wave episodes alone.

104 105 Table 5 continued: Time-Series Analyses of Mortality-Temperature Relationship

Study Population Exposure Outcome Results (Reference) Hunter Valley Temperature maximum, Mortality, morbidity Coronary deaths had a ‘V’ shaped relationship with thresholds of 23-27°C.MI NSW Minimum, relative from coronary heart was less apparent with increased temperature and decreased rainfall. Both (103) humidity, rainfall. disease. SCD and MI showed a relationship with weather.

5 Australian cities. Temperature thresholds Excess mortality Excess mortality noted for al cities with extreme heat. Socio-economic status (102) and Temporal Synoptic had little effect. Strongest effect within the 65+ yrs age group. Index Brisbane Daily average temperature Daily mortality A ‘comfort zone’ of 21-24°C was identified. Mortality increased at (104) and temperature maximum temperatures greater than 24°C. and minimum.

Adelaide 30 hottest and 30 coldest CCU admissions for CCU admissions on ‘hot’ days were more likely to be male, over the age of (194) days over 1 calendar year Atrial Fibrillation 65 years and live alone.

Adelaide Daily maximum Morbidity and mortality During heatwaves, total ambulance transport increased by 4%.Total hospital (79) temperature>35°C on 3 admissions increased by 7%. Total mental health admissions increased by consecutive days. 13% and Ischaemic heart disease admissions increased by 8% among people aged 65-74 years. Total mortality, disease- and age-specific mortality did not increase, apart from a small increase in mental health-related mortality in people aged 65-74years.

105 106 Table 6: Studies of morbidity associated with heatwave events. Type of study Outcome Risk factors for measured Population Exposure Results (Author, date) measured outcome Retrospective descriptive People admitted to 10 day heatwave Emergency 94 patients with heat-related Risk factors for being admitted to survey. emergency in Adelaide, department illnesses. hospital with a heat related illness (Faunt et.al., 1995) (120) departments of February, 1993 presentations for 78% with heat exhaustion. during a heatwave included: being four hospitals in heat-related 85% ≥ 65 years, 20% from elderly, living in an institution, Adelaide during a illness. institutions, 30% had poor having impaired cognitive ability, heatwave. Mortality. mobility, 48% lived alone. taking diuretics, multiple Peak presentation after 4 days medications, and with coexisting of heat. illnesses. Mortality =12%. 17% of survivors required an increased level of care after discharge.

Descriptive study People admitted to Heatwave in Excess hospital 11% increase in hospital Being elderly and having comparing hospital hospitals in Cook Chicago, July admissions. admissions. preexisting medical conditions, discharge data during a County during 1995. Reasons for Mainly the elderly, those especially cardiovascular disease, heatwave with heatwave. admission. presenting with heat-related diabetes, renal disease, nervous corresponding non- Co-morbid illnesses and acute renal failure, system disorders, emphysema or heatwave period. conditions. and those with coexisting epilepsy, increased the risk of being (Semenza et.al, 1999) (97) conditions: esp. cardiovascular admitted to hospital with severe disease, diabetes, renal disease, heat-related conditions during the nervous system disorders, heatwave. emphysema and epilepsy.

Population study of Residents of Heatwave in the Excess hospital Despite increased mortality Hot weather had little effect on relationship between Greater London UK, 29 July-3 admissions during the heatwave, no emergency hospital admissions in mean daily temperature August, 1995 corresponding increase in London during heatwave of 1995. and emergency hospital emergency hospital admissions Results suggest that people who die admissions, using time- was observed. of heat-related illness may do so series analysis rapidly, before medical assistance (Kovats, et al, 2004) (83) can be reached.

Population study of Residents of the 5 consecutive Excess hospital At least 4 consecutive hot and Duration of heatwave was found to relationship between Veneto Region, heatwaves admissions. humid days were required be the major risk factor for hospital admissions and Italy. occurring during before a significant increase in hospitalisation, rather than intensity heatwave intensity, the summer hospitalisation for heat or timing of heatwave across the duration and timing months of 2002 associated diseases and summer months. during the summer and 2003. respiratory diseases was months. Mastrangelo observed. et.al, 2007) (100)

106 107 Table 6 continued: Studies of Morbidity associated with heatwave events.

Type of study Risk factors for measured Population Exposure Outcome measured Results (Author, date) outcome Case-series study Residents of Heatwave Excess ambulance Ambulance transports increased by For those ≥ 75 years, heatwave comparing risks to metropolitan episodes in transports, hospital 4%; cardiac-related transports for days were associated with health during Adelaide. Adelaide, from admissions, and ≥75years group fell by 7%. Total reduced risk of ambulance heatwave and non- 1993-2006. mortality. hospital admissions increased by 7%. transportation and hospital heatwave periods Ischaemic heart disease admissions admission for ischaemic heart (Nitschke et.al, increased by 8% for 65-74 age disease and respiratory disease, 2007) (79) groups. Decreased admissions for and a reduced risk of dying due ischaemic heart disease and to cardiovascular disease. respiratory disorders for ≥75 age group. No increase seen in total mortality, For 65-74 years, and ≥75 age group mortality due to cardiovascular disease fell.

Population study Residents of the Oppressively Number and spatial Over 4 year period, average number Ambulance calls increased on of the relationship city of Toronto, hot days during variability of of ambulance call increased by 10% extreme hot weather days, between Ontario, Canada. the summer ambulance calls. on extremely hot days. The spatial especially from city, lakeside ambulance calls months of distribution of calls differed on recreation areas, industrialised and extreme heat. 1999-2002. extremely hot days when compared to areas with older housing, an (Dolney other days. elderly population, and minority et.al,2006) (101) population groups.

Prospective Patients admitted Heatwave in In-hospital mortality 21% of patients died in hospital. Most patients found at home, observational to intensive care Chicago, 12 (heat- 33% of survivors had severe lived in homes without air study, with 1 year units in Chicago, July-20 July, stroke).Functional functional impairment at discharge. conditioning, were taking follow-up. with a diagnosis 1995. status at discharge. After 1 year, 28% of those discharged medication, most commonly (Dematte et.al), of heat-stroke. Morbidity and from hospital had died, and none had diuretics, and had co-existing 1998 (29) mortality at one year. an improved functional status. medical conditions, especially hypertension, alcoholism, coronary artery disease, diabetes. Survivors with high levels of disability at discharge were more likely to have died after 1 year.

107 108 Table 6 continued: Studies of Morbidity associated with heatwave events.

Outcome Risk factors for measured Type of study Population Exposure Results measured outcome (Author, date) Observational study. Patients admitted to Heatwave in In-hospital mortality In-hospital mortality was Poor prognostic factors were: being (Misset et.al, 2006) intensive care units France, 1-19 (heat-stroke). 62.6%. The mean survival discovered at home or a care facility (30) in French hospitals, August 2003 time was 13.1 days. rather than a public place; having severe with diagnosis of alterations to physiological variables heat stroke and/or receiving vasoactive drugs within the first 24 hours of admission, being treated at a hospital without air- conditioning.

Prospective Patients admitted to Heatwave in In-hospital mortality 58% of patients died in Compared to survivors, non-survivors observational study, a hospital in Lyon, France, 1-19 (heat-stroke). hospital, 71% had died by were more likely to live in a care-facility, with 2 year follow- France, during a August 2003 Mortality and 2 years. Most survivors have had long-term therapy with anti- up. (Argaud et.al, heatwave, with a morbidity at 2 years. had a diminished hypertensive drugs, and have coexisting 2007) (28) diagnosis of heat functional status at 2 years. medical conditions (especially stroke. cardiovascular, neurological, and psychiatric). Poor prognostic factors at admission included high fever, coma, anuria, cardiovascular failure.

Descriptive survey- Patients who died at Heatwave in In-hospital mortality In-hospital deaths 80% of patients who died of heat-related based study. a hospital in Lyon, France, 1-19 (heat-related deaths). increased by 32% during causes were older than 75 years. More (Vanhems, 2003) (32) France, 8-19 August, August 2003 the survey period, women died than men. 2003. compared to the corresponding period for the previous year. 41% of in-hospital deaths were heat-related.

Retrospective cohort Patients seen in Heatwave in Demographic, At 1month, 18% of Greater dependence on others for care, study, comparing emergency France, 1-19 clinical, and patients had died. At 6 cardiomyopathy and/or pneumonia, survivors and non- department in a August 2003 laboratory data of months, 20% of those previously taken psychotrophic survivors of heat- hospital in Paris, survivors and non- discharged from hospital medication, more severe clinical picture related illness. over a 7 day period, survivors. Short-term had died, or 35% of total on presentation, and altered mental state. Davido et.al, 2006) with a heat-related and long-term cohort. At (195) medical problem. mortality. 12 months 45% of cohort had died.

108 109 Table 7: Studies of risk factors for heatwave associated illness and death. Type of Study Outcome Population Exposure Risk factors identified Protective factors identified (Author, date) measured Meta-analysis Six case-control studies in Heatwaves in Heat-related Being confined to bed, not leaving home  Having a working air- (Bouchama et.al, US and Europe, involving Europe and USA, deaths daily, being unable to care for oneself, conditioner, (112) 2007) 1065 heatwave-associated from 1980-2003 having a psychiatric illness,  Visiting a cool deaths. having cardiovascular or respiratory illness, environment taking psychotrophic medications.  Participating in social activities.  Being institutionalised for those unable to look after themselves

Case-control People older than 70 years Heatwave in Heat-related Needing home help, remaining in the city study. (Foroni who died during August 1- Modena, Italy, death during summer, having pre-existing et.al ,2007) (84) 30, 2003, living in Modena, August 2003. illnesses, loss of at least one activity of Italy. daily living.

Case-control People aged ≥65 years who Heatwave in Heat-related Lack of mobility especially if confined to Using any type of cooling device, study lived at home and died France, August deaths bed. Pre-existing medical conditions dressing lightly, visiting cooler (Vandentorren during a heatwave in 4 2003 especially mental disorders, cardiovascular places. et.al, 2006) (109) regions of France. disease, neurological diseases, high blood pressure. Being a manual worker. Inadequate insulation, having a bedroom located under the roof

Case-control 63 people who died in Chicago heatwave, Heat-related Living alone, not leaving home daily, Having a working home air- study (Naughton heatwave of heat-related July 29-August 6, deaths having cardiac or psychiatric illness, living conditioner, participating in group et.al, 2002) (108) causes, matched controls. 1999 on top floor of building, low income. Rate activities, having a pet, taking of deaths was highest in very elderly. extra showers/baths during heatwave. Fans not significantly protective.

Case-control 339 people ≥24years old, Chicago heatwave, Heat-related Being confined to bed, living alone, not Having working air-conditioner, study (Semenza who died in Chicago July 14 -July 17, deaths leaving home each day, being unable to care having access to transport, having et.al, 1996) (20) heatwave in 1995, matched 1995 for self, living on top floor of a building, social contacts. controls. having known medical problems.

109 110

Table 7continued: Studies of risk factors heatwave associated illness and death. Type of Study Outcome Population Exposure Risk factors identified Protective factors identified (Author, date) measured Case-control !7 people who died of heat- Heatwave in Heat-related Having a mental illness, Having a working air conditioner. study (Kaiser related causes, and 34 Cincinnati, Ohio, deaths et.al, 2001) (111) controls. 1999

Case-crossover People aged 35 or over who Apparent Odds ratio of Increasing age, female sex, being study died in 4 Italian cities from temperature dying on a day unmarried/widowed/divorced, having (Staffoggia et.al, causes other than injury, (previous and same of 30°C depression, pre-existing psychiatric 2006)(113) 1997-2003. day) of 30°C compared to conditions, heart conduction disorders, compared to 20°C. 20°C apparent cerebrovascular disease, living in a nursing temperature. home.

Case-only People who died in 50 US Extremely hot days Susceptibility to Age ≥ 65 years, diabetes, non-white race, analysis cities, 1989-2000 -daily minimum dying on low level of education, female, coexisting (Medina-Ramon temperature >99th extremely hot atrial fibrillation, dying outside a hospital. et.al, 2006) (115) percentile for that days. city.

Case-only People aged ≥65 who died in Extremely hot days Susceptibility to Diabetes, non-white race analysis Wayne County, Michigan, - daily, or three dying on (Schwartz, 2005) USA, 1984-1998. day average extremely hot (116) minimum days. temp.>99 percentile

Prospective Patients admitted to a Heatwave in In-hospital Living in a care facility, long-term therapy observational hospital in Lyon, France, France, 1-19 mortality, with anti-hypertensive drugs, coexisting study. (Argaud during heatwave, with August, 2003. mortality at 2 medical conditions (especially et.al, 2007) (28) diagnosis of heatstroke. years cardiovascular, neurological, psychiatric disorders), fever, coma, anuria, cardiac failure at presentation.

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Table 8: Factors found to increase the risk of heat-related death. Odds Ratio Factors associated with Author, Date (95% Confidence increased risk (Reference) Interval) Bouchama, 2007 (112) 6.44 (4.5-9.2) Confined to bed Vandentorren, 2006 (109) 7.52 (4.25-13.31)

5.5 (2.5-12.1) Semenza, 1996 (20) Bouchama, 2007 (112) 2.97 (1.8-4.8) Unable to care for ones-self, Vandentorren, 2006 (109) 3.23 (1.84-5.69)

4.1 (2.0-8.4) Semenza, 1996 (20) Foroni, 2007 (84) Receiving assistance in the 3.77 (2.22-6.39) Semenza, 1996 home 6.2 (2.9-13.4) (nursing) (20) Loss of at least one activity of Foroni, 2007 (84) 5.03 (3.03-8.35) daily living Living in a nursing home Stafoggia, 2006 (113) 1.61 (1.41-1.84) Living alone Naughton, 2002 (108) 5.4 (1.8-15.90) Semenza, 1996 (20) 2.3 (1.4-3.5)

Bouchama, 2007 (112) 3.35 (1.6-6.9) Does not leave home each day Naughton, 2002 (108) 4.5 (1.7-11.7)

Semenza, 1996 (20) 6.7 (3.0-15.0) Vandentorren, 2006 Absence of social contacts 6.12 (3.32-11.30) (109) Being a widows or widower Stafoggia, 2006 (113) 1.5 (1.33-1.69) Medina-Ramon, 2006 Dying outside of hospital 1.066(1.036-1.098) (115) Hospital admission in previous Foroni, 2007 (84) 6.46 (4.14-10.81) year Bouchama, 2007 (112) 2.48 (1.3-4.8) Vandentorren, 2006 Cardiovascular disease 3.19 (2.08-4.90) (109) 7.2 (2.5-20.8) Naughton, 2002 (108) 2.3 (1.5-3.6) Semenza, 1996 (20) Heart conduction disorder Stafoggia, 2006 (113) 1.77 (1.38-2.27

111 112

Table 8 cont. Factors found to increase the risk of heat-related death. Cerebrovascular disease Stafoggia, 2006 (113) 1.46 (1.33-1.61) Medina-Ramon, 1.035 (1.010-1.062) Diabetes 2006 1.17 (1.04-1.32) Schwartz, 2005 (116) Bouchama, 2007 (112) 3.61 (1.3-9.8) Vandentorren, 2006 5.86 (2.75-12.490 (109) Psychiatric illness 1.7 (1.39-2.09) Stafoggia, 2006 (113) 5.7 (1.9-16.8) Naughton, 2002 (108) 14.0(1.8-6.33) Kaiser, 2001 (111) 3.5 (1.7-7.3) Semenza,1996 (20) Cognitive impairment Foroni, 2007 (84) 3.38(2.16-5.28) Vandentorren, 2006 Neurological disease 4.67 (2.42-8.99) (109)

Respiratory disease Bouchama, 2007 (112) 1.61 (1.2-2.1) Semenza, 1996 (20) 2.2 (1.0-4.9) Vandentorren, 2006 Cancer 2.79 (1.53-5.08) (109) Vandentorren, 2006 Obesity 2.00 (1.30-3.10) (109) OR increased with Stafoggia, 2006 (113) increasing age Medina-Ramon, 1.02 (1.005-1.034) for ≥ 65 Being elderly 2006 (115) years Naughton, 2002 (108) Rate of death highest for ≥75 years old. Female sex Stafoggia, 2006 (113) 1.45 (1.37-1.52)

Vandentorren, 2006 2.33 (1.33-4.09) Living on top storey of (109) building 4.0 (1.7-9.3) Naughton, 2002 (108) 4.7 (1.7-12.8) Semenza, 1996 (20) Bedroom directly under Vandentorren, 2006 2.16 (1.26-3.69) roof (109) Vandentorren, 2006 2.75 (1.56-4.85) Lower socioeconomic (109) status 3.1 (1.0-9.7) Naughton, 2002 (108)

112 113

Table 9: Factors found to decrease the risk of heat-related death.

Odds Ratio Factors associated Author, Date (95% Confidence with lower risk (Reference) Interval) Having a working Bouchama, 2007 0.23 (0.1-0.6) home air- (112) conditioner 0.12 (0.0-0.3) Naughton, 2002 (108) 0.03 (0.0-0.2) Kaiser, 2001 (111) 0.2 (0.2-0.2) Semenza, 1996 (20)

Using a cooling Vandentorren, 2006 0.53 (0.33-0.84) device, including (109) air-conditioner or fan. Access to air Semenza, 1996 (20) 0.2 (0.1-0.5) conditioned lobby in apartment building.

Visiting another air- Bouchama, 2007 0.34 (0.2-0.5) conditioned place, (112) 0.3 (0.2-0.5) outside the home, (20) during the Semenza, 1996 heatwave. Participating in Bouchama, 2007 0.4 (0.2-0.8) social activities (112) 0.3 (0.1-0.7) Naughton, 2002 (108) 0.7 (0.5-0.9) Semenza, 1996 (20)

Have access to Semenza, 1996 (20) 0.4 (0.2-0.4) transportation Having a pet Naughton, 2002 (108) 0.3 (0.1-0.8) Semenza, 1996 (20) 0.6 (0.4-0.9)

Taking extra baths Naughton, 2002 (108) 0.3 (0.1-0.9) or showers during heatwave Dressing lightly Vandentorren, 2006 0.35 (0.23-0.53)

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Table10: Examples of guidelines for personal strategies during heatwaves. Organisation/ Country Titles Source Multi-lingual (Reference) Centre for Diseases A Prevention Guide to Promote Internet sites Yes Control (CDC), Your Personal Health and Safety Atlanta, USA. (196). Available all year. Tips for Preventing Heat-Related Illness (197), Heat Stress in the Elderly (198), Safety in a Power Outage (153), Frequently Asked Questions (199).

National Health Service A Guide to Looking After Yourself Internet site Yes. Also in (NHS), and Others During Hot Weather Pamphlet available at Braille, audio- United Kingdom (200) GP clinics, pharmacies, cassette tape, large hospitals, Citizens’ print. Advice Bureau, care organisations, etc. Available all year.

Toronto Public Health, Summer Safety Tips to Beat the Internet sites. Yes Canada Heat (152). Child Car Safety In Hot Weather Available all year. (201). Tips for Using a Fan (134) Landlords also sent Help Pets Beat the Heat (202). written information at Medications and the Heat (203) beginning of summer. Heat, Drugs and Alcohol (204). Advice to Landlords (205)

Queensland Health, Public Health Fact Sheet: Heat Internet site No Australia Related Illness: Signs, Treatment Available all year. and Prevention (206)

Queensland Ambulance Prevent Heat Related Illness for Service. Seniors (207) Prevent Heat Related Illness: babies and young children (208)

Department of Human Preventing Heat Related Illness Internet site No Services, Victoria, (209) Available all year. Australia. First Aid for Heat Stress (210)

Care of Children in Hot Weather This document in (211) Arabic NSW Health, NSW, Media release: People Warned to Internet site available No Australia. Stay Cool and Safe in the Heat (212) all year. Media release at beginning of summer

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Table11: Heatwave Response Plans - Public Health Interventions: Toronto

Interventions Country/City Name of Plan (Reference) Heat stress indicator Warning system Toronto, Hot Weather Response Plan Synoptic system Two tiered system: (149, 213) Canada Heat alert, Extreme heat alert.

Also, maximum indoor temperature threshold of 32 degrees Celsius to act as threshold for activation of protective measures for rooming houses, facilities for the elderly. Proactive Education and training:  Education sessions provided by Public Health Nurses during year for public (especially seniors, childcare providers, schools, landlords of boarding rooms), and for staff of health care organisations.  Red Cross conducts first-aid training for staff and volunteers of community agencies serving vulnerable people. Database of high risk people:  Community agencies develop and maintain registries of their at-risk clients.  Resource packages sent to organisations/individuals who deal with vulnerable adults.  Assessment of rooming homes and boardinghouses by Public Health staff. Assistance provided to develop 'Heat Contingency Plan'. Boarding homes:  Landlords provided with 'Hot Weather Protection Plan' packages that contain advice, including '3 Simple Steps for implementing a hot weather plan'. Information:  Libraries display heat health messages during summer.  Information brochures distributed to out-patient rooms.  Heat Information tear-off pads distributed to the elderly, via organisations that provide services to the elderly such as Meals on Wheels. Drinking water:  Drinking fountains in the park checked to see if they are functional. Planning:  Meeting of Hot Weather Response Committee before summer commences to finalise role of each agency. Media:  Media event held at start of summer in which health personnel answer media questions  Risk-group specific information placed on the web. .Utilities:  Pilot project planned for Health Department and electricity company to provide assistance to low-income earners to own and operate air-conditioner. Follow-up:  Regular post-summer review and report of the operation of the heatwave response efforts.  A survey of participating community agencies to assess outreach efforts is due for completion in 2008.

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Reactive Alert:  Alert notice sent to hospitals and community agencies. Coordinated by Toronto Public Health. Information:  Media release about heat alerts and precautions to take, cooling centre locations. Outreach:  Public health nurses make telephone contact and conduct home visits for registered at-risk clients, and distribute 'Beat the Heat' brochures.  Public health staff visit rooming houses to check on implementation of heat plans. Cooling centers:  Libraries and community centers used as cooling centers.  Extra cooling centers opened with Extreme Heat Alert.  Cooling centers provide air-conditioning, drinking water, snacks. Homeless:  Hours of drop-in centers extended for use by homeless .Provide meals and other services.  'Park Ambassadors' visit city parks to provide information about telephone numbers and cooling centers to the homeless.  Bottled water made available to homeless through street patrols of frequented areas. Transportation:  Transport Tokens distributed to the homeless requiring transportation on public transport to cooling centers.  Transportation to cooling centers provided by Red Cross if needed.  Opening hours of public pools extended. Heat Telephone service:  Information telephone line operated 9am-9pm each day by Red Cross for information, advice, and referral. Can send help if needed. Utilities:  Cease any disconnection of water supplies. Elderly:  Six extra short stay beds made available in nursing homes for use by the elderly. Pets:  Hot weather safety messages for pet owners.

116 117 Table12: Heatwave Response Plans - Public Health Interventions: Philadelphia

Interventions Country/City Name of Plan (Reference) Heat stress indicator Warning system Philadelphia, Hot Weather Health Synoptic system Three-tiered system: USA Watch/Warning System  watch, (117, 126, 131, 182)  alert,  warning: 3 levels of severity.

Proactive Information:  Media outlets given background information about minimising exposure to heat during heatwaves, and encouraged to broadcast heat -related stories. Buddy system:  Recruitment and training of Block Captains.  Block captains sent heat information to distribute to residents in their area. Warning System:  Synoptic-based warning system allows a 5-day forecast period.

Reactive Information:  Media broadcast information about alerts, how to keep cool, and recommendations on checking neighbours, friends who are sick, elderly, isolated. Telephone service:  Heatline activated, 8 am-12 midnight. This is operated by Philadelphia Corporation for Ageing, operating with the same number usually used for Seniorline. Nurses also staff the call-center. The telephone help line number is displayed on a large electronic billboard on top of building visible over much of Philadelphia. Buddy System:  Block captains, as well as general public encouraged to check on elderly, sick, isolated friends, neighbours, family, and to ensure adequate fluids and ventilation are available. Homeless:  Outreach activities extended to day time hours. Utilities:  Halt to shut off of water or electricity supplies for duration of heat alert. Cooling centers:  Hours of operation of air-conditioned senior centers extended. Outreach:  Home visits by mobile teams of Health Department staff to people identified through the Heatline as being in need of assistance.  People at high risk moved to air-conditioned shelters if necessary. Nursing Homes:  Department of health contacts nursing homes and other facilities for the aged to offer advice on heat protection for residents. Personnel:  Increased number of emergency service and medical personnel on duty.

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Table 13: Heatwave Response Plans - Public Health Interventions: Chicago

Interventions Country/City Name of Plan (Reference) Heat stress indicator Warning system Chicago, USA Extreme Weather Heat index Two-tiered system: Operations  Heat watch, Plan (131, 157)  heat warning

Proactive Census of vulnerable elderly:  The Department of Ageing, through a Seniors Well-Being Task Force encourages public and private organisations to identify elderly people who need monitoring and assistance.

 Organisations including church groups, Postal Services, utility companies are asked to be on alert for elderly people showing signs of distress in hot weather.

 People concerned about their health are encouraged to register for a 'well-being check' during a heat warning period. They are automatically contacted by telephone before a heatwave arrives, receiving a recorded message with safety tips and information

Outreach:  At heat watch stage, at risk individuals receive an automatic telephone call to provide safety tips and information.

Building standards:  Nursing homes are checked for adequate ventilation,  People are asked to be sure that they can open their windows unassisted

Information:  Brochures distributed

Reactive Information:  At the ‘heat watch’ stage, brochures are distributed that include “Heat Tips”, and information about how to register for a ‘well-being check’. Cooling centers:  Cooling centers, and free bus and personal driver transportation, provided 24 hours a day during heat warning.  Hours of senior centres extended. Outreach:  Disability advocacy organisations asked to check on their clients.  Health Department and Housing Authority staff monitor nursing homes, and emergency rooms of hospitals.  Mobile assessment teams of nurses carry out ‘well being checks' on people in their homes, and over the telephone. Traffic:  Extra tow-trucks deployed to assist stranded motorists. Water:  Water pressure around the city monitored, illegally opened water hydrants repaired.

118 Table14: Heatwave Response Plans - Public Health Interventions: Rome

Interventions Country/City Name of Plan (Reference) Heat stress indicator Warning system Rome Heat Health Watch Warning Synoptic system Three-tiered system: System (74, 117)  Attention  Alarm  Emergency Proactive Information:  From May to September information regarding warnings, and illness prevention guidelines for the general public and specific high-risk groups, is available on the web site of the Department of Social Policies and Health Promotion. These guidelines are developed with assistance of the Association for General Practitioners. Planning:  Organisations involved with heatwave planning include general practitioners, health care agencies, hospitals, health resorts, homes and social institutions for the elderly, media.

Outreach:  At-risk individuals can register to receive attention via the tele-assistance scheme during a heatwave.

Training:  A network of volunteers and social services staff are trained to manage emergencies during the summer.

Reactive Telephone service:  Registered individuals are connected via a telephone system to an operative center providing information, 24 hour advice, food and drug deliveries, emergency calls, and activation of assistance networks.

Information:  Information bulletins on health department web site regarding the location of air-conditioned social centers and public buildings.

Outreach:  A network of trained volunteers, social service staff and street units are utilised during an emergency to assist people identified as needing assistance. Table15: Heatwave Response Plans - Public Health Interventions: Catalonia, Spain.

Name of Plan Heat stress Interventions Country/City Warning system (Reference) indicator

Catalonia, Action Plan to Prevent the Temperature 2 warning levels: Spain effects of a heatwave on  Level 1 (Extreme the health. (POCS) (155) maximum temperature warning)  Level 2 (Heatwave warning)

Each of the levels can be given or cancelled for coastal and inland areas independently. Proactive Surveillance and prediction of meteorological risk situations  Collection of daily temperature and mortality data

Extensive Dissemination of Information regarding preventive measures:  Distribution of leaflets to general public from Primary Health Care Centres, chemists, and outpatient departments of acute care hospitals.  Talks/education sessions for general public and professional groups.  Programs on local radio stations, articles in newspapers, information on the internet.  Neighbours association newsletters.  Letters sent to all people registered as at risk.  Telephone information service.  Information and advice available from chemists.

Telephone service:  Throughout summer, a telephone service operated by the Ministry of Health provides information and advice to the general public, and will coordinate with healthcare services if vulnerable people are detected.  Specific recommendations  Dissemination of preventive and special care recommendations to health care personnel working in Primary Healthcare Centres, Mental Health Care Centres, social and health care centres, hospitals, and mental health admission centres.

Action Plans Devised  At commencement of summer, each Primary Healthcare Centre, mental health service, home care support service, hospital and aged care home to have an action plan detailing measures to support high-risk clients during a heatwave, including preventive strategies and communication protocol.

Census of at-risk people  At commencement of summer, each Primary Healthcare Centre, in conjunction with social health services, prepares and updates a database of people in their care considered to be at high risk of heat-related illness.  Those registered receive a letter regarding preventive measures.

Program to increase air-conditioning  Program instituted in 2007 to install air-conditioning and awning blinds in Government housing.

Computer database:  Development of a computer application for use by town and city councils to create a database containing details of people identified as being at risk of heat-related illness and a catalogue of 121

resources available in the municipality including cool shelters and means of transportation to these. Reactive Distribution of fans/portable air-conditioners  Made available by Ministry of Health to Healthcare Centres and Chemists for distribution to public, hospitals, mental health centres.

Contact high-risk groups  Those registered as at high-risk visited in their homes, or treated at Primary Healthcare Centres.

Telephone service  Provides advice, information, and referral service. Linked with a medical emergency service.

Provision of information  Chemists  Media/internet  Announcements using megaphone in small villages during heatwave

Transportation of high-risk people to air-conditioned shelters.

Activation of emergency resources if necessary.

121 Table16: Heatwave Response Plans - Public Health Interventions: United Kingdom

Name of Plan Interventions Country/City Heat stress indicator Warning system (Reference) England, UK Heatwave Plan for Day and night 4 levels: England (156) temperatures,  Summer preparedness and with thresholds varying for summer planning different regions.  Alert and readiness  Heatwave action  Emergency. Proactive Responsibility  Department of Health has responsibility for overall planning, in collaboration with Met Office, Health Protection Agency and other NHS agencies.

Surveillance  Establish surveillance system, monitoring calls to NHS and GP visits, to assess health impact of heatwaves.

Information and Advice  Public information leaflet prepared by Department of Health. Distributed through GP practices, pharmacies, NHC offices, Citizens Advice Bureaus, Nursing homes, volunteer organisations (200).  Website established by Department of Health with same information and links.  Factsheet for health and social care professionals regarding health risks, risk reduction strategies, need to identify and assess at-risk individuals in advance (214).  Factsheet for managers and staff of residential and nursing homes (215).

Identification of high-risk individuals  Primary Care Trusts and local social services to identify high-risk individuals, mainly those already receiving care.  Develop special care plans for use with high-risk individuals during heatwave by social care services, voluntary sector, families, and carers.  Ensure awareness of families and carers regarding protective measures.

Staff  Plan for availability of extra staff.  Encourage additional staff training; ensure awareness of heat-related health-risks, risk groups, especially psychiatric patients.

Hospitals, residential homes and nursing homes  Thermometers installed in each room. Printed sheets organised on which to record indoor temperature four times a day during heatwave.  Establish cool rooms or cool areas in each establishment, with ambient temperatures no greater than 26°C. Organise schedule for use of cool areas, with the most vulnerable given priority.  Ensure sufficient staff available during heatwave.  Provide email address to local authorities/emergency planning personnel.  Ensure adequate supplies of drinking water, ice.

Long term  Encouraging planting of trees;  Use of reflective paints, blinds, and insulation of buildings;  Increase energy efficiency transport, appliances, and cooling mechanisms. Media  Warning broadcast to public by television and radio stations 3 days in advance of heatwave.  Media used to raise awareness, provide advice.

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Reactive Communication between Health services  Department of Health initiates communication regarding warnings and advice to staff from National, through to Regional and Local levels.

Surveillance  Monitor NHS phone calls from public, and GP visits, as indication of health effects and system response.

Information and advice to public  Department of Health continues to provide written advice, website.  Media provides information about warning and advice. Outreach  Daily visits/phone calls to previously identified individuals by health and social care staff.  Public urged to visit anyone they know who lives on their own and might be at risk (200). Hospitals, residential and nursing homes  Ensure supply of cold drinks  Monitor and record indoor temperatures  Maintain and utilise cool areas  Seek early medical assistance in individual becomes unwell  Ensure discharge planning takes into account temperature of intended accommodation, and activity level of individual concerned.

123 124 Table 17: Heatwave Response Plans - Public Health Interventions: Shanghai

Interventions Country/City Name of Plan (Reference) Heat stress indicator Warning system Shanghai, Shanghai Heat Health Synoptic system Three-tiered system: (150) China Warning System  Level 1: 40-59 excess deaths predicted  Level 11: 60-79 excess deaths predicted  Level 111: 80 or more excess deaths predicted.

Proactive Education  Early in summer heat health information is promoted using the media  Special education programs are provided for the elderly and people who work in hot environments.  Official presentations are made to the public regarding heat health Information  Pamphlets are distributed to the public and vulnerable groups.

Reactive Information:  Information provided about the heatwave using TV, radio stations, newspapers. Outreach:  Community health professionals visit the elderly in city areas, especially those with chronic disease. Water and electricity supplies and cooling devices are checked. Advice is provided. Medications  Doctors treating mental disorders, endocrine, nutritional and metabolic diseases are advised to pay attention to the adverse effects of some drugs, and to use alternative treatments if thermoregulation is compromised by current treatment. Treatment  Hospitals are prepared to receive heat affected individuals.

124 125 Table 18: Heatwave Response Plans - Public Health Interventions: Dayton

Interventions Country/City Name of Plan (Reference) Heat stress indicator Warning system Dayton, Ohio Southwest Ohio Synoptic system Two-tiered system: USA Heat Watch/Warning  Heat alert: 1-2 excess System (166, 167) deaths predicted  Heat emergency: 3 or more excess deaths predicted

Proactive Buddy system  ‘Buddy system’ established, by enlisting local citizens to check on elderly neighbours during heat warnings. Participating agencies  More than 150 organisations involved in heat response plan. Each agency has an ‘Agency Action Sheet’ with description of their role in the plan.

Reactive Heat alert Communication with participating agencies  Over 150 ‘Heat Mitigation Partners’ contacted by fax or email by city health commissioner  Includes police, fire department, Red Cross, television stations, media, coroners’ office, recreation agencies, elderly citizens’ organisations, local utilities.  Each agency has an ‘Agency Action Sheet’ outlining actions to take. Information  Government media department sends information to media outlets with details of heat alert and recommendations for reducing health risks.  Includes suggestions for those at home, warnings about not leaving children or pets in cars, guidelines for the safe use of fans, identification of vulnerable people.

Heat emergency Communication  Faxes and emails used to communicate elevated warning to ‘Heat Mitigation Partners’ as above, with media asked to announce the heat emergency in weather reports. Utilities  Utilities requested to discontinue cutting of services due to non-payment during alert period. Buddy system  Buddy system implemented to check on the elderly. Telephone helpline  “Help Link” telephone service implemented during heat emergency days to answer heat-related questions. Cooling centres  Recreation centres made available during daytime as ‘cooling centres’. Emergency services  Police, fire departments, hospitals on alert to treat heat-related illness. Surveillance of heat-related deaths  Coroners’ office asked to record the number of heat-related deaths during the alert.

125 126 Table 19: Heatwave Response Plans - Public Health Interventions: Milwaukee

Interventions Country/City Name of Plan (Reference) Heat stress indicator Warning system Milwaukee, Plan for Excessive Heat Heat Index Utilises National Weather Service (81, 168, 169) (216) USA Conditions 2007 (Temperature and criteria : Humidity)  Excessive Heat Outlook: potential for event to occur in 3-7 days  Excessive Heat Watch: conditions favorable or event to occur in 12-48 hours  Excessive Heat Advisory/Warning: Event expected or occurring Proactive Coordination  Role of Milwaukee Health Department Participating agencies  Includes over 20 agencies, including Government Departments concerned with ageing, disability, mental health;, Salvation Army, Interfaith, and agencies serving those who are homeless, mentally ill, have low-income, disabled, or elderly; police, fire department, schools, media.  Pre-summer meetings to update plan, and clarify roles and responsibilities;  Communication tests between participating agencies. Cool shelters  Prepare and distribute map of cool shelters, including hours of operation, access for disabled.  School-based ‘Cool Spots’ program for heat-relief at designated playgrounds. Education  Heat information to health professionals, carers, volunteers routinely in contact with elderly.  Information pamphlets distributes; these are specific to target groups and multilingual.  Hospitals to educate patients/family about heat health, heat and medications, prior to discharge.  Red Cross operated 24-hour ‘Health Tips’ information line for duration of summer. Identification of high-risk individuals  Agencies to identify and enroll at-risk clients into established registries if appropriate, or establish procedures to check on at-risk clients during heat alert. Nursing homes  Ongoing monitoring of conditions  Annual communication regarding heat-related needs of clients. Media  Media encouraged to publish stories regarding heat illness and prevention  Use of Heat Index in weather reports to improve public familiarly with concept.

Reactive The response is linked to National Weather Service advisory thresholds, and modified if required according to surveillance data, with specific roles for the coordinating body and agencies. Specific measures include:  Active surveillance of heat illness and death, with data coming directly from health professionals via an established fax-line, hospital emergency departments, and local health departments.  Operation of a 24-hour telephone hot line, and internet site, to provide information and resources for the public and health professionals.  Extended hours of operation of designated cool shelters, with assistance at centres, and with transportation as needed.  Daily contact with at-risk registered clients, and advice for staff, volunteers and clients of involved agencies.  Advice to sponsors of outdoor events to consider rescheduling programs.  Power companies cease shut-down due to non-payment, and monitor power consumption and availability.

126 127

Table 20: Heatwave Response Plans in Australia and New Zealand.

Location Heatwave Response Plan Intentions (reference) Victoria Research and pilot projects currently Intend to develop a Statewide Heatwave underway, as part of the Victorian Response Plan at the Local Government or Climate Change Adaptation Primary Health Partnership level (218). Program, to inform the development of a Statewide Heatwave Response Plan (217).

NSW Heatwave Pilot Project for the Central Coast of NSW. In operation since September, 2007 (37)

Queensland Queensland Heatwave Response Intend to review the plan in early 2008 (170) Plan (39). In operation since 2004.

Tasmania No plan (219)

South Australia No work done yet, plan to develop a Intend to develop one in the future. response plan in the future (220)

Western Australia No specific heat event response (221) Have written extensive document "Health Impacts of Climate Change" that lists some strategies needed (222)

Northern Territory No plan (223). No intention of developing one in the future.

ACT No plan (224)

New Zealand No heatwave response plans in New There has been some consideration of this, but Zealand (225) nothing has been developed yet.

127 128

Table 21: Comparison of Heatwave Response Plans in Queensland and NSW.

Name of Response Plan NSW Central Coast Pilot Heatwave Project (37, 173) Queensland Heatwave Response Plan(39, 172)

Heat stress indicator Temperature Heat Index

Warning criteria Hot Day: Heat Warning  Maximum daytime temperature greater or equal to  Heat Index expected to reach or exceed 34 on 37°C. two or more consecutive days, in Brisbane. Heatwave:  Maximum daytime temperature greater to, or greater Extreme Heat Warning than 37°C for more than 2 days.  Heat Index expected to reach or exceed 38 on any one or more of the days identified in the Extreme event: Heat Warning.  Maximum daytime temperature equal to, or greater than 37°C for an extended time in conjunction with bushfires and/or power failure.

Public health interventions ‘hot day’ warning ‘heat warning’

 Media release to provide preventive information to the  Queensland Health issues an alert to relevant public. Government agencies, triggering readiness for  Division of General Practice notified. impending heatwave and associated health effects. General Practitioners provided with heat health information for ‘extreme heat warning’ their own use.  Media statements are issued by Queensland Information pamphlets prepared for distribution to general Health and other agencies such as the public by health care providers. Ambulance Service, to provide the public with information regarding appropriate behavior to avoid heat-related illness.

 Electricity, water and telephone agencies are requested not to terminate services to anyone during a heatwave.

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