Cold exposure has played a major part in many wartime battles. In addition to frostbite, the effects of hypothermia on military campaigns appears throughout history. Accidental hypothermia is an unintentional decrease in core body temperature. Alexander the Great was comatose from hypothermia, as were many of his warriors. Hannibal lost about 20,000 of his 46,000 troops in 219 B.C. while crossing the Pyrenees.
Baron Larrey, Napoleon's physician, returned to France in 1812 with 350 healthy soldiers from the initial 12,000. George Washington's troops were battered by the winter of 1777-78, with nearly 10 percent dying from the effects of the cold.Cold-related casualties reported during World War I included 115,000 British, 80,000 French and 38,000 Italian troops. In World War II, the Germans suffered 100,000 and U.S. troops 90,000 cold injuries. About 10 percent of the total U.S. deaths in Korea were cold-related. During the 1982 Falklands War, hypothermia, frostbite and trench foot were common.
Cold-related tragedies have afflicted skiers, hunters, climbers, swimmers and the indigent. Mt. McKinley, Mt. Everest and Mt. Hood have had numerous cold-related injuries among mountain expeditions.
Hypothermia is widespread during all seasons in the United States. Urban settings account for most of those hypothermia cases. Even the warm state of Florida has hypothermia victims.
First aid
Accurate field measurement of the core body temperature is often not practical. Low-reading thermometers are most often not available. Prolonged field care should be avoided whenever possible, and the rescuer must prevent further heat loss. First aid includes:
- Using dry insulating materials to prevent heat losses.
- Not using stimulants and oral heated fluids (such as coffee, chocolate) since they are not useful.
- Gently handling severely hypothermic victims and not allowing victims to exert themselves.
- Not massaging cold arms or legs.
- Gently removing wet clothing. Passive external rewarming with insulation works for mild hypothermia.
- Wisely using rewarming methods. Although skin rewarming suppresses shivering, and impedes the rate of core rewarming, it may be the only option when the victim is isolated from medical care.
- Using active external rewarming options, which include radiant heat, warmed objects placed on the victim, and body-to-body contact. Care must be used not to burn victims with hot objects, including commercially produced "hot packs." Total body contact rewarming may be hazardous. If used, heat application should be confined to the body's trunk.
- Seeking medical attention.
Prevention
These precautions should be considered if you're going into outdoor cold temperatures:
- Having excellent physical conditioning with adequate rest and nutrition.
- Being accompanied by a partner.
- Wearing thermal insulation.
- Changing wet inner clothing promptly.
- Avoiding dehydration. Do not eat snow (melt it first) since it requires significant energy to convert ice to water.
- Keeping the head covered. An uncovered head can lose a large percentage of the body's total heat production.
- Using synthetic insulating materials such as Gore-Tex and Thinsulate.
- Following the mnemonic COLD. The army uses COLD in reference to insulation with clothing: Clean, Open during exercise to avoid sweating, Loose layers to retain heat and Dry to limit conductive heat losses.
Alton Thygerson is a professor of health sciences at Brigham Young University.