The evaluation and management of accidental hypothermia.

Accidental hypothermia is defined as an unintentional decrease in core body temperature to below 35 degrees C. Hypothermia causes hundreds of deaths in the United States annually. Victims of accidental hypothermia present year-round and in all climates with a potentially confusing array of signs and symptoms, but increasing severity of hypothermia produces a predictable pattern of systemic organ dysfunction and associated clinical manifestations. The management of hypothermic patients differs in several important respects from that of euthermic patients, so advance knowledge about hypothermia is prerequisite to optimal management. The paucity of randomized clinical trials with hypothermic patients precludes creation of evidence-based treatment guidelines, but a clinically sound management strategy, tailored to individual patient characteristics and institutional expertise and resources, can nonetheless be gleaned from the literature. This article reviews the epidemiology, pathophysiology, clinical presentation, and treatment of accidental hypothermia. Initial evaluation and stabilization, selection of a rewarming strategy, and criteria for withholding or withdrawing support are discussed.