AKU-6- 90-002 C3

FROSTBITE AND OTHER COLD

ALASKA SEA GRANT COLLEGE PROGRAM

EOUCATION PUBLICATION NO. 7 1990 FROSTBITE AND OTHER COLD INJURIES

DEBORAH MERCY Alaska Sea Grant Marine AdvisoryProgram Anchorage, Alaska

SG-ED-07 1990 Price $400

Aaska Sea Grant College Program UniversityOf Aaska Pa radarks, 138 rving II i a.radar ks, Aaska 99775-hOWO ;9O7j A7d-7ORA

FISHERIESSAFETY AND SURVIVAL SERIES Elmer E. RasmusonLibrary Cataloging-in-PublicationData.

Mercy, Deborah Frostbite and other cold injuries,

Fisheries safety and survival series! SG-ED-07!

1. Frostbite Study andteaching. I. AlaskaSea Grant CollegeProgram. II, Title. III. Series; Sea grant education publication; no. 7.

RC88.5.M47 1990

About the Author

DeborahMercy has been instructional media specialist for the Alaska SeaGrant Marine AdvisoryProgram in Anchoragesince 1986. She has produced several videotapes for the Marine AdvisoryProgram, and servesas managingeditor for theALaska Marine Resource Quarterly. Mercy'sexperience also includes broadcast journalism and commercial fishing,

Acknovvledgments

This bookand the videothat accompaniesit would not havebeen possible without the time, effort, andcomments provided by the followingpeople. Content Specialists: Scott Sullivan, R.N.,Providence Hospital, Anchorage; Jerry Dzugan,Alaska Marine Safety Education Association;and Todd Miner, Alaska Wilderness Studies, University of AlaskaAnchorage. InstructionalDesigner: Barry Willis, Universityof AlaskaAnchorage. Thanks also to the AlaskaWilderness Studies program for their generouscontribution of videofootage used in the program,

Editing of the bookletis by Kurt Byers,cover art is by KarenLundquist, and text formattingis by Ruth Olson.This projectwas funded by Saltonstall-KennedyFishery Development Funds administeredby the NationalMarine Fisheries Service under cooperative agreement number 86-ABH-00031.

This bookletwas produced by the AlaskaSea Grant CollegeProgram, which is cooperatively supportedby ! the U.S. Department of Commerce,NOAA Office of SeaGrant and Extramural Programs,grant no,NA90AA-D-SG066, project no. A/75-01 and A/71-01, and ! the University of Alaska with funds appropriated by the state. Table of Contents

What This Workbook Is About

Overview

SectionI. The Dangerof ColdInjuries

SectionII. Typesand Characteristicsof ColdInjuries Frostnip Superficial Frostbite Deep Frostbite Immersion Foot

SectionIII. Causesand Preventionof LocalizedCold Injuries Frostnip,Superficial Frostbite, Deep Frostbite, Immersion Foot

Section IV. Treatment of Cold Injuries Frostnip Superficial Frostbite Deep Frostbite Re-Warming After Re-Warming Immersion Foot Some Do's and Don'ts of Cold Treatment

Summary

Quiz Yourself

Quiz Answers

For More Information

We Need Your Comments Frostbite and Other Cold Injuries 1

What This Workbook Is About

This workbook provides general information on four types of cold injuries. The goal is to help increase awareness of the causes, characteristics, treatments, and prevention of cold injuries, and thus reduce the number of injuries suffered by people due to exposure to cold, wet, and hostile environments. This workbook, Frostbite and Other Cold Injuries, may be used alone or with the 16-minute video program of the same name, The workbook is part of the Fisheries Safety and Survival Series. Others in the series are A-2-031!, Shore Survival A-2-033!, and Mari ne Survival Equipment and Maintenance SG-ED- 06!. For help with using workbooks and the related videotapes in a classroom, a Facilitator's Notebook A-2-034! has also been prepared. The booklets and videos by the same titles are available from the Marine Advisory Program, University of Alaska, Carlton Trust Building, 2221 E. Northern Lights Blvd., Suite 110, Anchorage, AK 99508-4140, 907! 274-9691.

This booklet does not include everything there is to know about localized cold injuries. For sources of further information, see the "For More Information" section at the end of this book.

If you are studying the workbook and viewing the videotape as part of a group, your group facilitator will suggest ways to most effectively cover the material. If you are studying the material alone, we suggest you read through the workbook, and answer questions at the end as a revie~. Keep this workbook for future reference.

If you have any comments or suggestions after reading this workbook, please fill out and return the last page.

This information was compiled by the University of Alaska Sea Grant Marine Advisory Program, and was collected from a variety of sources, including Providence Hospital, Anchorage, and outdoor health and safety specialists. 2 Frostbite and Other Cold Injuries

Overview

Cold wind, rain, water, snow, and ice can be dangerous for the unprepared, causing minor to fatal cold injuries.

Localized cold injuries are frostnip, superficial frostbite, deep frostbite, and immersion foot, also known as , The first three injuries are characterizedby localized frozen tissue. Immersion foot is characterizedby cold, wet, non-frozentissues. Victims of cold injuries often recover completely,but in more severe cases, victims can lose one or more extremities or die.

Anyone who goesoutdoors must adopt the attitude that the only sure bet for preventing injury is to be prepared. You never know how your day is going to end, Understanding the causesof cold injuries is the best way to prevent them.

The purpose of this workbook is to help you identify, prevent, and treat cold injuries. The book describes:

~ The danger of cold injuries.

~ What causes cold injuries.

~ How to prevent cold injuries.

~ How to identify different cold injuries.

~ How to treat and care for cold injuries.

In addition to knowing the principles, techniques, and procedures in this workbook, it is also important to practice them. Frostbite and Other Cold Injuries 8

Section I: The Danger of Cold Injuries

It's January, and after days of tanner crab fishing you have the day off, The boat is anchored in a quiet bay, it's morning, and everyone has finished breakfast and is anxious to get off the boat and explore the shoreline, The skipper asks you to start the skiff's engine. It's cold and windy outside. But you' re accustomed to that, and since you will only be outside for a few minutes, you don't bother to put on your gloves.

The enginedoesn't start soyou adjust the choke.Now the coldis makingyour hurt, especiallywhen you touch metal. All of a suddenyou can't feel the engine metal and your hand feels like ice when you touch it with your warmer hand. You have developed a cold injury.

Cold injuries can happen in just a few minutes, or they can creep up slowly, over several hours or even days. Onset of cold injuries may or may not be sensedby the victim, but in either casethe injury can result in severetissue damage requiring , or in the worst case, death.

The tragedy about localized cold injuries is that they can almost always be prevented,

It was November and Zee Hyden had asked Lori to accompany him on a picnic and river boat ride. It was a mild day and they were enjoying their first date,

About 3:00 pm it started cooling off, so they decided to head home. But on their way, their boat got caught betweentwo rocks, flipped over, and drifted away. They managed to grab some food and make it to shore, wet and chilly, but uninjured. Seeing no alternative, they began walking home.

Zee and Lori had both drunk some wine with their picnic. The alcohol combined with the urgent feeling to return home cloudedtheir ability to make a safe decisionabout what they should do. They ended up walking for twenty-five miles, through boggy terrain with only a small amount of food all in tight fitting boots. Their soaking wet feet were tired, and beganto swell, hurt, and go numb, Eventually Lori began to hallucinate and Zeelost his ability to think clearly. They were suffering from hypothermia and immersion foot.

Finally they made it back to their car. Slowly they drove home and on to a hospital where they were treated for their injuries, It took six months before each regained all feeling in their . 4 Frostbite and Other Cold Injuries

Had Zee and Lori been familiar with the warning signs of hypothermia and immersion foot, and had they been able to make clear decisions, they could have acted to prevent these problems.

Knowing that cold water drains body heat twenty-five times faster than air, they would have tried to find a drier route home or sought help elsewhere. They would have known that avoiding wetness would also have helped prevent immersion foot, since it doesn't take freezing temperatures to causethis malady. They also would have known that when body temperature drops, hypothermia occurs,which can lead to further cold injuries, and that their restrictive clothing would obstruct blood supply to their extremities, which also would speed the onset of a cold injury.

Section II: Types and Characteristics of Cold Injuries

There are two broad types of cold injuries: freezing injuries frostnip, superficial frostbite, deep frostbite!, and non-freezing injuries immersion foot!. All four of these cold injuries are called localized cold injuries. Each differs in severity. The first three are characterized by local frozen tissues, while the latter is characterized by localized, non-freezing, cold, wet tissues.

Freezing injuries result from localized reduction in water to the cells due to freezing between the cells. Non-freezing injuries result from prolonged exposure to cool, wet conditions.

Frostnip

The least serious cold injury is frostnip. It is the freezing of surface . It can be painful and disfiguring if skin tissue is actually lost. Frostnip usually occurs in body areas that are thin, easily chilled, and often exposed directly to wind, moisture, or both, such as lobes, cheeks, the tip of the nose, and tips. Because it generally appears on the face, it can go unnoticed. It is helpful to have a friend along so you can both keep an eye on each other. If you are alone, periodically check your face with a mirror. Frostnip appears white, but the skin remains soft. A long-term effect of frostnip can be an increased sensitivity to cold. Frostbite and Other Cold Injuries 5

Superficial Frostbite

Superficial frostbite is the freezing of superficial tissues. If frostnip goes untreated it will developinto superficial frostbite, a more serious cold injury. It can occur on exposedfacial areas as well as the hands and feet. Often an early symptom is pain, but as tissues continue to freezethe pain will give way to numbness.However, symptoms vary with the individual most peoplenever feel pain; others never lose it. The injury appears white, waxy, and firm on the surface but soft when pushed. will generally form after thawing and re- warming, but long-term tissue damagecan often be minimized with proper treatment. Future sensitivity to cold can be a long-term effect.

Deep Frostbi te

If superficial frostbite goes untreated it will develop into deep frostbite, the most dangerousof the cold injuries. Freezing will continue to spread over skin tissues and move deeperinto muscle,bones, blood vessels,nerves, and even the organs. As with superficial frostbite, an early warning sign of deepfrostbite may be pain. However, sometimes no pain is felt and the injured area just becomes numb.

Deep frostbite appearswhite, sometimesblotchy, or purple if the injured area is large, such as an entire foot or hand. The surface and underlying tissues will feel cold and hard when pushed. The damage can be extensive, resulting in a major loss of tissue or even entire extremities. If not treated, the injury can become infected, which can lead to amputation or cause death. As with other cold injuries, there is increased sensitivity to cold.

Immersion Foot

Immersion foot, also known as trench foot, is unlike other types of cold injuries because rather than being caused by freezing temperatures, it usually occurs when wet feet are exposed for many hours to above-freezing, cold, wet weather. Prolonged cooling damages tissues and nerves. Immersion foot has traditionally been associated with infantry soldiers, cannery workers, and fishermen who wear boots and waders.

Immersion foot makes the foot appear mottled, red, waxy, and swollen. Long- term damage is minimal, although the area could remain more sensitive to cold. 6 Frostbite and Other Cold Injuries

Section III: Causes and Prevention of Localized Cold Injuries

Frostnip, Superficial Frostbi te, Deep Frostbite, Immersion Foot

Most of us are familiar with the most obvious causes of cold injuries and how to prevent them. Following is a summary of what causes freezing and non-freezing cold injuries and tips on how to prevent them.

~ Conductive heat loss, This is the process whereby heat moves from a warm body to a colder surrounding environment, such as to snow, cold water, cold air, or cold objects, All of these can freeze skin and will steal your body heat, leaving you vulnerable to cold injury. Conductive heat loss can be reduced if uncovered parts of the body are not exposed to cold materials.

~ Wet clothing. Dry clothes are necessary to keep the body warm. Wool when wet insulates better than cotton and most synthetic fabrics, Dry socks are especially important, so always have an extra pair available.

~ Contact with "supercooled" liquids such as gasoline or solvents. These liquids will remain fluid at temperatures well below freezing, but your skin will freeze when exposed to them, Contact with a "supercooled" liquid can cause instant freezing.

~ Cooling of extremities. When the body cools, blood flow slows in the extremities, This helps keep interior organs warm and reduces overall heat loss, but it also makes the extremities more susceptible to cold injury. The solution is to have enough warm, dry clothes to keep the body warm inside and out.

~ Hypothermia, Hypothermia is the total cooling of the body. Although it does not always cause a cold injury, it is usually present when an injury occurs. Hypothermia can be avoided by wearing warm, dry, layered clothing to keep body heat close to the body and protected from outside temperatures. Head and neck protection is particularly important.

~ Obstruction of blood supply to the extremities. Constrictive clothing, such as tight fitting boots or plastic boots which do not expand, can hasten onset of cold injury. This can be avoided by wearing loose fitting garments, dry socks, and proper fitting boots. Frostbite and Other Cold Injuries 7

~ Nicotineand alcohol.Both shouldbe avoidedin coldenvironments. Cigarette smoke, or nicotine from any source, constricts blood vessels and will aggravatelocalized cold injuries. Alcoholmay openup bloodvessels, which couldfight off frostbite,but that possiblebenefit is far outweighedby the loss in mentalcapacity suffered when drinking. When judgment is impairedby alcohol,a personmay increasetheir chancesof hypothermiaand further endanger themselves.

~ Dehydrationand lack of food.Fluids and foodare the body'sfuel. Without themthe bodywill not staywarm and thus will leavethe bodysusceptible to cold injuries.

Some Words about Immersion Foot Immersionfoot trenchfoot! is the mostnotable non-freezing cold injury. Many of the mechanisms listed above will cause immersion foot. Immersion foot usually occurswhen wet feet are continuouslyexposed to a near-freezing environment for days or weeks. Actual immersion of feet in cold water is not necessary.

Whencold water stealsheat from feet,blood vessels constrict, causing further cooling.Take precautions to avoidwet feet for prolongedperiods of time in a cold environment,and take the time to dry the feet and put on dry socks.During the FalklandWar, immersion foot was reduceddramatically by soldierssimply stopping for a moment to dry off their feet and put on dry socks.

Be Prepared

Simplyput, the bestprevention against localized cold injury is protection. Alwaysbe preparedfor rapid weatherchanges. When going anywhere outdoors, even if it is just for a drive, take sufficient clothing and checkweather conditions beforeleaving. Ask yourself,"If I don't makeit to my destination,can I stay warm and dry, or will I be susceptibleto a cold injury?"

Section IV: Treatment of Cold Injuries

The treatmentfor all localizedfrozen cold injuries is rapid re-warming.This minimizesblood circulation damage that followsthawing. If the injury is 8 Frostbite and Other Cold Injuries superficial, the warming may usually be done in the field, However, if the injury is serious, frozen tissues should not be thawed if there is any chance of re- freezing. Ideally, the victim should be rushed to a hospital or clinic where they can be kept warm and the injury protected after it has been thawed.

Frostnip

Frostnip is not considered a serious injury, and treatment can be carried out in the field. Immediately re-warm the injured area to prevent development of more serious injury. Frostnip responds to body heat, so simply cover the affected area with your hands. If frostnip is on your hands, place them in your armpits or any other place that is warm,

Super fieia/ Frostbite

Superficial frostbite is a surface injury that is a bit more serious than frostnip. The treatment is the same. Re-warm the affected area, keep it covered, and get out of the cold as soon as possible.

Deep Frostbite

The ideal environment for rapid re-warming of deep frostbite injuries rarely exists unless you are in an urban area with hospitals nearby. In remote situations, you may have to walk or ride in a cold helicopter or plane. Do not thaw the frozen part if you cannot keep it thawed. Let it stay frozen. Walking on a frozen foot will produce less damage than if it is thawed and re-frozen. If the frozen part is a foot, you will need to be carried to transportation once thawing occurs. Unfortunately, walking on a frozen foot may be the only choice for survival. In this case there may be no way to avoid further damage.

Re- Warming

The proper method for re-warming a deep frostbite injury is to ! remove clothing or other items that may impair circulation, ! place the injured area in a warm water bath between 95 and 105 degrees Fahrenheit. Be careful. If the water is hotter, it will cause further damage to the tissues with a . If the water is too cold, re-warming will be too slow. The water must not feel uncomfortable to an uninjured person's hand. Do not allow the damaged area to touch the sides of the tub, Frostbite and Other Cold Injuries 9

The frostbitten hand or foot, like a block of ice, will cool the warm water. Maintain the correct temperature by adding more warm water. When warm water is added,the injured part should be removed until the water is thoroughly mixed. Re-warming of the damagedtissue will take about twenty to forty minutes. The water bath should continue until there doesnot appear to be further improvement in skin color and tissues have completely thawed.

Most but not all peopleexperience some pain during the warming process.The pain usually stops shortly after thawing has occurred.

After Re-Warming

After re-warming, the patient must be kept warm and the injured tissues should be elevated and carefully protected, Water baths should be repeated at least oncea day.Length of treatment will differ with the severity of the injury.

Unless frostbitten tissues are damagedbeyond repair, blisters will form. The blisters are a normal part of the healing process.To avoid infection, every effort must be made to protect the blisters from rupturing. Sterile gauze or cotton should be placed between frostbitten fingers or toes to absorb moisture.

Healing can take as long as several weeks or months, and it is vital to keep the affected areas clean. Cigarette smoking or other use of should be avoided, since nicotine will further reduce already deficient blood supply to the injured tissues.

Immersion Foot

Treatment is to get the victim off their feet, out of the cold, warmed up, and dry.

After re-warming, keep injured feet clean, dry, and elevated to help relieve swelling. Keep the victim warm so his or her injuries receive ample blood supply, Additional treatment may be necessary,but it should be administered by a doctor.

Some Do's and Don'ts of Cold Injury Treatment

Do not re-warm a severelyfrozen part if there is a chancethe part will be re- frozen. Freezing causes a set of sharp ice crystals to form in the tissue. If 10 I'rostbite and Other Cold Injuries

melting and re-freezing occurs, the sharp ice crystals become larger and cause even more damage to the already injured tissues. If re-warmed tissue freezes again, the damage may be irreversible,

Do not rub the frozen part with your hands or with snow because both are abrasive to the skin,

Do not use open fires, ear heaters, stoves, or similar sources of dry heat to thaw frozen tissue. These heat sources cannot be closely regulated and they cause dehydration. Because the frozen part is numb, the victim also could suffer a burn without knowing it.

Do not bump a frozen body part against anything because the injury could become worse. A bump may open brittle skin or send toxins created by the injury through the body.

Summary

Generally, cold injuries are caused by a reduction in blood supply to a localized area. The results are varied. Cold injuries can have little or no effect, or they ean cause serious disability or death.

Key Points To Remember

Cold injuries are a threat when you are exposed to below freezing temperatures, or when you are exposed to above freezing temperatures for prolonged periods of time.

The four types of localized cold injuries are: frostnip, superficial frostbite, deep frostbite, and immersion foot.

Cold injuries can develop in minutes, hours, or take several days, depending on the type of exposure.

Usually the first sign of frostbite is pain. Take care to notice when an extremity hurts, or to notice if a friend is getting a white patch on his or her face or other exposed extremity.

Depending on severity or treatment, cold injuries can leave no or few , or they can cause permanent disability and death, Frostbite and Other Cold Injuries 1Z

To prevent cold injuries:

Use commonsense. Keep warm, Wear proper layered clothing that doesnot constrict circulation,

Eat high-energy foods and drink plenty of water or juice.

Avoid overexertion.

Do not exposeskin directly to cold air, water, metal, wind, or "supercooled" liquids.

Do not smoke cigarettes or anything else containing nicotine.

Do not drink alcohol becauseit will impair your ability to make gooddecisions,

If clothing is wet, change into dry clothes.

Rapid re-warming:

For frostnip and superficial frostbite, re-warming can be done in the field.

For deepfrostbite, re-warming should not be done until the injury is out of danger of being re-frozen.

For immersion foot, feet should re-warmed and rested.

The best protection against a cold injury is not allowing it to happen. Be prepared for rapid weather changes.Whether you are going outdoors to work, play, or travel, take extra clothing, food, and water to protect yourself in case something happens.

Rememberthat practicing these techniques and proceduresis very important to preventing frostbite and other cold injuries, But this is not all there is to know about frostbite and other cold injuries. For sourcesof more information, seethe "For More Information" section at the end of this book. 12 Frostbite and Other Cold Injuries

Quiz Yourself

Part I

Directions: Circle "T" if the statement is true and "F" if the statement is false. Refer to the workbook if necessary.

], T F For immersion foot to occur the temperature must be below freezing.

2.TF Freezing injuries are the result of a localizedreduction in water to the cells due to freezing between the cells.

3.TF Superficial frostbite is the least dangerouslocalized cold injury.

4. TF The earliest symptom of frostbite is pain.

5. TF The re-warming water temperature should range between 95 and 105 degrees Fahrenheit.

6, TF Do not thaw frozen tissues if you cannot keep the tissue thawed.

7, T F Bumping a frozen body part will not harm the injured tissue.

8. T F Loose fitting clothing can cause a cold injury.

Part II

Directions: Fill in the spaceswith the correct word or words. Refer to the workbook if necessary.

1. The best way to prevent a cold injury is to:

2. What are the three causes of cold injuries? I'rostbite and Other Cold Injuries 13

3. What is conductive heat loss?

4, Why should nicotine be avoided in cold environments?

5. Why should drinking alcoholic beveragesbe avoidedin cold environments?

6, What are the differencesbetween the four most commontypes of cold injuries?

7. What is a "supercooled"liquid? Why should"supercooled" liquids be avoided?

8. What are the long-term effects of localized cold injuries?

9. Why would you walk on a frozen foot?

10. Why is dry heat dangerousfor a localizedcold injury?

11. How long doesit take for a localizedcold injury to develop? 14 Frostbite and Other Cold Injuries

Part III

Directions: Read the following story and chooseone of the three coursesof action listed at the end of the story.

It is late November,the temperature is a crisp minus 25 degreesFahrenheit and the wind is a steady 20 mph with gusts to 45 mph. Wind has tom siding from your shed exposing dry goods stored there.

Dressedwarmly, tools in hand, you head out into a wall of swirling snow. Gropingfor nails through heavygloves is a frustrating chore,but you needto repair the siding now.So you take off your glovesto finish hangingthe plywood, until you feel intense cold and numbnessin your hands.

Which of the following three coursesof action would you take? Circle your answer.

1. Ignorethe coldand leaveyour glovesoff, becausethe work will be complete in just a few more minutes.

2. Get out of the cold and warm up your hands. Eat something, drink a warm fluid, and rest.

3. Get out of the cold, warm up your hands, smoke a cigarette and drink a cup of hot coffee,then return outside to finish the job.

Quiz Answers

Part I

1. False, Immersion foot occurs with prolonged exposure to cold, slightly above freezing temperatures,

2. True. Freezing injuries are the result of a localizedreduction in water to the cells due to freezing between the cells.

3, False. Frostnip is the least serious cold injury, It occursonly on the outer layers of skin. frostbite and Other Cold InJ'uries 15

False. Although the earliest symptom of frostbite can be pain, somecold injuries immediately become numb.

True. If the water is colder,the re-warmingwill be too slow.If hotter,the water may burn the injury.

True, If a frozen part is thawed and re-frozen, tissue damagewill be even greaterthan if the areais left frozen.But sometimes,walking on a frozen foot may be the only choicefor survival. In this case,there may be no way to avoid further serious damage.

False. If an injured area is bumped against something, it will make the injury worse,It may openbrittle skin or sendtoxins createdby the injury through the body.

False. Loosefitting clothing will not causea cold injury. Quite the opposite, it is necessary to wear loose clothing so that blood circulation is not restricted in any part of the body. Restricted blood flow can cause a cold injury.

Part II

Be prepared.Carry extra loosefitting clothingand bootsif you can.Also haveextra water and foodon hand and do not invite a problemthrough unnecessary exposure to cold, smoking cigarettes, or drinking alcohol,

l! Allowing unprotectedskin to be exposedto a cold,wet, or windy environment or to "supercooled"liquids or cold objects,! hypothermia, or the coolingof the entire body,and ! alteration of bloodsupply to the extremitiesby injury, illness,drugs, nicotine, or constrictingclothing or footgear.

Conductive heat loss is the processwhereby heat movesfrom a warm bodyto a colderenvironment, as whenunprotected hands are exposedto cold air. Conductiveheat lossis reducedif uncoveredparts of the bodyare not exposed to the cold.

Cigarette smoke,or nicotine from any source,constricts blood vesselsand will aggravate local cold injuries. Ii'rostbite and Other Cold Injuries

Drinking alcoholic beveragesmay open up blood vessels,which could fight off frostbite. However, judgment is usually so poor when drinking that a person may increase his or her chances for suffering hypothermia and other cold injuries.

Frostnip is the freezing of surface skin. Ear lobes, cheeks, the tip of the nose, and finger tips are often affected by exposure to cold wind, water, or surfaces,

Superficial frostbite is a more serious cold injury that attacks superficial tissues. It can occur on exposed facial areas as well as the hands and feet. Pain is typically an early symptom of superficial frostbite, but as tissues continue to freeze the pain will give way to numbness.

Frostbite is the most dangerousof the cold injuries. Freezing spreadsover skin tissues, and it moves into deeper structures such as muscle, bones, blood vessels, nerves, and organs.

Immersion foot is the most common non-freezing cold injury. It usually occursin above-freezing,cold, wet weather when wet feet are exposedto these conditions for many hours, days, or weeks.

A "supercooled" liquid remains fluid at temperatures well below freezing. An example of a "supercooled" liquid is gasoline or antifreeze.

A long-term result of all types of localized cold injuries can be increased sensitivity to cold. Damage from deep frostbite can be as little as increased sensitivity to cold or as extensive as a major loss of tissue or an entire extremity. If not treated, the injury can become infected and without further treatment, can cause death.

You might walk on a frozen foot if your survival depends on it. However, the long-term damage to the foot will probably be extensive.

Dry heat cannot be regulated, and it can cause dehydration, Because the frozen part is numb, a burn can easily happen without the victim' s knowledge,

Cold injuries can develop in minutes, hours, or several days. Frostbite and Other Cold Injuries 17

Part III

Answer ¹1

WrongI Your hands are suffering from conductive heat loss becausethey are being exposed to cold air and metal nails. Both the air and the metal steal heat from fingers, leaving them in danger of cold injury,

It only takes a few minutes to freeze your hands and you may not even feel it happen. Sometimesthe endangeredarea will never feel pain. It will simply become numb. Therefore, if you do not stop to warm your hands you will likely suffer a cold injury.

Answer ¹2

This is the best of the three options. You may finish the job if you warm up your entire body,including your hands. It may take a little longer to completeyour project, and you may need to go indoors to warm up. But if you take a break to warm up soon enough, a cold injury should not occur.

Cold injuries are not always the result of an accident. They can be avoided if you take the time to prevent them. If you feel cold and have accessto a warm area, get into the warm place. Eat something. Food is the body's fuel, it keeps the body warm. Drink something warm. Fluids are the key to preventing dehydration. And allow your body to rest, so it can regain goodblood circulation to all extremities. Before returning outdoors to finish the job, put on plenty of warm clothes, including a hat, gloves, and boots, and do not take them off unless you feel too warm or until you have returned indoors. Adequate protection from the cold is the key to preventing a cold injury,

Answer ¹3

This is both correct and incorrect. If your hands are numb, you need to get out of the cold immediately. Drinking hot fluids is a goodidea but smoking a cigarette is a bad idea. Cigarettes constrict the blood vessels,slowing circulation required to keep the cold area warm, If your hands are not completely re-warmed and you expose them again to the cold, they may suffer a cold injury. In addition, banging them against a hammer will only further aggravate the injury. 18 Frostbite and Other Cold Injuries

For More Information

Hypothermia,Frostbite and Other ColdInjuries. JamesA, Wilkerson,M.D., Cameron C. Bangs, M.D., John S. Hayward, Ph.D. 1986. The Mountaineers, Seattle, Washington,

Clinical Experiences in Treatment and Rehabilitation of Frostbite in Alaska. William J. Mills, Jr., M.D. 1960. Technical Report 59-24, Arctic Aeromedical Laboratory, Ladd Air Force Base, Alaska.

Fisheries Safety and Survival Series, Hypothermia A-2-031!, Shore Survival A- 2-033!,Facilitator's Notebook A-2-034!, and Marine Survival Equipment and Maintenance SG-ED-06!. Available from the Marine Advisory Program, University of Alaska, Carlton Trust Building, 2221 E. Northern Lights Blvd., Anchorage, AK 99508-4140, 907! 274-9691.

Medicine for Mountaineering, James A. Wilkerson, M.D. 1985. The Mountaineers, Seattle, Washington,

Hypothermiaand Frostbitein Cross-CountrySkiers. Nathan J. Smith, M.D. Pp. 346-357in CommonProblems in Pediatric Sports Medicine. Year Book Medical Publishers, Inc., Chicago.

Alaska Medicine. William J, Mills, Jr., M.D. March 1973,Vol. 15, No. 2,

Videotapes Marine Survival Series. Hypothermia MAPV-1!, Cold Water Near- MAPV-2!, Sea Survival MAPV-3!, Shore Survival MAPV-4!, Marine Survival Equipment and Maintenance MAPV-ll!, and Frostbite and Other Cold Injuries MAPV-17!. Available at $15.00 from the Marine Advisory Program, University of Alaska, Carlton Trust Building, 2221 E, Northern Lights Blvd., Anchorage, AK 99508-4140, 907! 274-9691. Frostbite and Other Cold Injuries 19

We Need Your Comments Letus know what you think ofthis workbook, and the video that goes with it. Weare also interested in hearingabout any instance of coldinjury, how it occurred,how it wastreated, and what its short- and long-termeffects were. Pleasewrite your commentson this page,tear it out, and sendit to the Alaska SeaGrant Marine Advisory Program address on the previouspage. QKIVERSITYOFALASKA FAIRBANKS The University of Alaska Fairbanks providesequal educationand employmentfor all, regardlessof race,color, religion, national origin, sex, age, disability, status as a Vietnamera or disabled veteran, marital status, changesin marital status, pregnancy,or parenthood pursuant to applicablestate and federal laws.