Lethal hypothermia – a sometimes elusive diagnosis

Accidental hypothermia is an uncommon problem that affects people of all ages, but particularly the elderly. This review briefly outlines the aetiological factors that may predispose to hypothermia, with particular reference to the effects of sepsis, although the specific situation of cold-water immersion is not addressed. A more detailed analysis of the pathophysiology of hypothermia then examines the cardiovascular, haematological, neurological, respiratory, renal, metabolic, and gastrointestinal systems. Clinically relevant findings are highlighted and some associated management points are related to the physiological changes. Most of these changes are reversible on rewarming, and are resistant to pharmacological manipulation; some of the pathological effects are related more to the process of rewarming than to the hypothermia itself.

Hypothermia refers to a situation where there is a drop in body core temperature below 35 degrees C. It is a potentially fatal condition. In forensic medicine and pathology, cases of hypothermia often pose a special challenge to experts because of their complex nature, and the often absent or nonspecific nature of morphological findings. The scene of the incident may raise suspicions of a crime initially, due to phenomena such as terminal burrowing behavior and paradoxical undressing. An element of hypothermia often contributes to the cause of death in drug- and alcohol-related fatalities, in the homeless, in immersion deaths, in accidents and in cases of abuse or neglect, making the condition extremely relevant to forensic medical specialists. The aim of this review is to give an overview of the pathophysiological aspects of hypothermia and to illustrate different aspects relevant to forensic medical casework.