HYPOTHERMIA

What To Do When It Strikes

Recognizing the symptoms of hypothermia and knowing how to treat it could save a life — perhaps even your own.

By Jane Johnson

In recreation, when we plan, advise, and make policy decisions using the best information available to us, we try to be responsible for the health, safety, and well-being of others. But when we set pool or beach hours and safety standards, deal with senior citizens and their related problems, or take a busload of campers on a trip, how often do we consider potential hypothermia in our plans?

Hypothermia, often called "exposure", can occur in all seasons and in many of the areas that touch our private and professional lives. Victims can be found among senior citizens in underheated homes, swimmers in cold water on a windy summer day, boaters who fall overboard, and unprepared backpackers, hunters, skiers and hikers.

Hypothermia can be defined as a cooling of the body core (brain and other vital organs in the chest and abdomen) below 95-96 degrees fahrenheit. A drop of 1 to 2 degrees causes our bodies to shiver, thus creating more heat through involuntary movement. If, because of external conditions, shivering fails to restore proper body temperature, the core temperature will continue to drop. The victim will feel cold, tired, and will experience muscular weakness and exhaustion. Between 95 and 91 degrees F the victim experiences speech difficulty, sluggish thinking, clumsiness, stumbling, falling, slow reactions, mental confusion and disorientation. He may still be able to bend over and pick up a mitten, but zipping up a parka is a real challenge. At 94 degrees the body loses its ability to warm itself without outside help.

The shivering stops when the core temperature drops below 90 degrees. The victim's muscles become rigid and his movements become jerky, although he still has some contact with reality. At 85 degrees he will probably become irrational and between 85 and 81 degrees he will lapse into a coma, with a weak pulse, erratic heartbeat, and shallow breathing. At temperatures between 80 and 75 degrees death will occur, and this entire process could happen in less than two hours. (See Figure 1)

The cause of hypothermia is that the victim's body is losing more heat than it can generate. Body heat can be added through muscular activity, nourishment from food, and such external sources as fire, sunshine, and hot food and drink. The body loses heat through:

CONDUCTION — the transfer of heat from a warm object to a cooler object (a cold gas pump handle)

CONVECTION — the transfer of heat through the air (which would be increased with rising wind velocity)

EVAPORATION — when liquid on our skin passes into the air (Our bodies lose heat 32 times faster when wet than when dry.)

RADIATION — the loss of body heat to a cooler object not in contact with it through infrared rays (especially through our heads on a cool night) and

RESPIRATION — breathing in cold, dry winter air and breathing out warm, moist air (dehydration can be a problem because our bodies can lose several liters of liquid during exertion on a cold day).

The very young and the very old have difficulty retaining body heat. The infant's "body thermostat" is not yet finely tuned, while the elderly have reduced ability to feel and respond to cold, can't shiver well, and have very little subcutaneous fat.

Both alcohol and tobacco also upset the body's heat controlling mechanism. Liquor causes the blood vessels to dilate in the extremeties, and thus heat is lost in response to internal, rather than external conditions. Conversely, tobacco causes the vessels to constrict and can cause a 10 degree drop in skin temperature in the fingers and toes.

Illinois Parks and Recreation 26 January/February 1983

In order to prevent hypothermia, we must know how to combat the effects of cold, wind, and moisture. Dressing appropriately is the most important. If we dress in layers, we can remove or add clothing in order to keep comfortably warm under changing conditions. The sweat we shed to cool off may make us chilly later on. A turtleneck T shirt, with a warm wool shirt over it, followed by a sweater, a windbreaking shell, and a vest will provide much more flexibility than a single heavy winter jacket. Clothing that wicks moisture away from the skin (wool, polypropelene, orlon or blends) is better than cotton which absorbs and holds moisture. Blue jeans and corduroy retain moisture, have very little insulating power, and should be avoided. Mittens are warmer than gloves, and a warm hat is essential, since at 5 degrees F we can lose 70% of our body's heat from our heads. "When your feet are cold, put on your hat," is a skier's universal truth. In order to keep out the wind, a tightly woven or windproof layer is advisable.

Figure 2: Fetal Heat Escape Lessening Posture (HELP) can add 50 percent to survival time by conserving body heat. You need life jacket to practice it

The cold may also be kept at bay by the frequent eating of high energy snacks such as candy, nuts, and "gorp" (good ole raisins and peanuts). We need to eat more than usual when we are exercising in cold conditions. (For instance, a cross country skier can burn more than 650 calories per hour.)

If the winter skier is a summer sailor or swimmer, he needs to know that he may experience symptoms of hypothermia after spending as little time as an hour in 65 degree water. Swimmers and boaters awaiting rescue in cold water will survive longer if they are wearing life jackets that insulate their upper bodies from heat loss in the water. The single victim can draw his knees up and assume a fetus position to protect the areas of highest heat loss (head, groin, and sides of chest). He should move as little as possible to avoid disturbing the water around him, and should keep his head out of water. (See Figure 2) If there are several life jacketed people in the water, they should huddle together chest to chest. (See Figure 3) The insulating value of clothing should not be overlooked. Clothing will not drag the swimmer down and can create air pockets that help keep him afloat.

Treatment for the victim of hypothermia is rewarming. The core of the body should be rewarmed first, so if the victim is conscious, he should be given warm, sweet liquids. Putting heating pads or canteens of warm to hot water next to the areas of heavy heat loss (head, groin, and sides of chest) will hasten warming. If a tub is available, the victim's torso can be immersed in warm (100-110 degrees) water while the limbs hang out. When far from the comforts of civilization, the entire party should stop, build a fire, construct a shelter from the wind and wet, change the victim's wet clothing for dry, and give him hot food and drink. In extreme situations, the stripped victim should be put in a sleeping bag with a stripped, warm companion so that skin to skin contact will begin to restore warmth to the victim's body.

Figure 3: Huddling can "pool" body heat and let two or more victims survive to 50 percent longer in cold water

If the victim was chilled rapidly, as from a fall into a mountain stream, then his body core will still be warm and he can be rewarmed rapidly. However, if he has been in water a long time, or wandering lost in the woods, care must be taken to warm him slowly, or the rush of cold blood to the less cold core will drop the body's temperature even lower, causing shock and possible heart failure within 2 to 3 hours of rewarming.

A victim of hypothermia, either from near drowning in cold water or from exposure to winter cold, may look dead, be stiff from muscle rigidity, have no perceptible pulse and bluish skin color, and still be alive. In hospital emergency rooms attendants know that, "No one is dead until he is warm and dead."The record for cold water immersion without brain damage is 38 minutes. So

(Continued on p. 32)

ABOUT THE AUTHOR:

Jane Johnson, Winnetka, a commissioner of the Glencoe Park District and a member of the Board of Directors of the Illinois Association of Park Districts, has been active in the IAPD for several years. She is Co-Chairperson of the 1983 Conference Committee. She is a Certified Cross Country Ski Touring Instructor, United States Ski Association: is a Certified Examiner. USSA, and Nordic Ski Patrol Candidate. USSA, Ms. Johnson is employed as a sales person, advertising specialties, premiums and executive gifts, David Scott Industries.

Illinois Parks and Recreation 27 January/February 1983

HYPOTHERMIA

(cont. from p. 27)

DO NOT GIVE UP! Warm the victim and give CPR if needed and if you are qualified. Once you start CPR, don't stop. (One victim was revived after five hours of CPR.)

Hypothermia can be experienced in an indoor pool during a scuba diving class or in the mountains in winter. Fatigue, panic, inexperience, inadequate food and poor judgment are contributory factors. Where it occurs is not as important as recognizing its symptoms and knowing how to help the victim before it becomes a serious, life-threatening situation.

Treatment: 1. Prevent further heat loss.

2. Rewarm as safely and rapidly as possible.

3. Rewarm the core before the body shell.

4. Avoid serious complications by handling the victim very gently and getting him to a hospital as soon as possible.

Illinois Parks and Recreation 32 January/February 1983