Fluid intake during flight helps prevent dehydration and makes up for profuse sweating. Crew members should be encouraged to drink fluids as conditions permit, especially in anticipation of periods of physical exertion. Although heat stress causes Army aircrew members the most significant problems, they cannot overlook the physiological effects of cold on the body. Because Army aircrews must operate in all types of environments, they must understand how the body reacts to cold-temperature extremes. For example, during World War II, the U.S. Army experienced 90,535 cases of cold injury, including several thousand cases of high-altitude frostbite in aircrews.
Many factors influence the incidence of cold injury.
If troops are in a static defensive position, the incidence of injury drops because they have time to take care of their bodies. Individuals under 17 or over 40 years of age seem to have a predisposition to suffer cold injury as do those who have previously suffered from it. Fatigue level, organizational discipline, individual training and experience, and physiological factors all affect the tendency of individuals to experience cold injury. Nutrition, activity, and the ingestion of certain drugs and medications also influence the incidence of cold injury. A cold injury may be either superficial or deep.