BACKGROUND

Historically, cold Injury, hypothermia and frostbite have been a severe problems for military units on the battlefield.1 While not common in modern conflicts, the potential exists for large numbers of these casualties in war and during training.2,3 Cold injury requires two things: a low absolute temperature and an exposure duration. In general, the human body contains the mechanisms to preserve core body temperature and extremities even if limb perfusion is temporarily impeded in order to preserve core body temperature. When these mechanisms are overwhelmed, the result is permanent tissue damage. The ultimate mechanism of injury involves a combination of direct cold injury to the cells, direct intracellular and intercellular ice formation, ischemia from thrombosis of the vasculature, and reperfusion injury.4 The patients that are afflicted with cold injury generally fall into one of two categories: those involved in industrial accidents and those unable to escape their environment. Patients in the military predominantly will fall into the category of inability to escape the environment. Unlike other types of injuries, all forms of cold injury are potentially preventable with knowledge, equipment, and foresight. Acclimation to the environment provides some protection while those of African descent have increased susceptibility to cold injuries.5

Increased rates of frostbite occur at extreme high altitude secondary to ambient temperature decreases and microcirculatory changes that occur at altitudes greater than 17,000 ft.6,7