Exposure

Exposure, sometimes called hypothermia is a normal hazard of temperate wilderness. It occurs when a person's core body temperature falls below 33.7C (92.6F). If a person is wet, in a mild wind, it can occur in less than an hour at temperatures as high as 15°C (59°F).

The basic early symptoms are uncontrollable shivering, stiffness and confusion. The conclusive evidence is a cool or cold stomach. If the hypothermia has not yet advanced to a critical stage, basic treatment is to warm the person in a sleeping bag. People with hypothermia may have such depressed metabolisms that they can no longer heat themselves. However, if the hypothermia has become severe - the victim is confused or unconscious - it is critical not to warm them suddenly. Evacuation would be the preferred option, with warming undertaken in a controlled medical environment. Sudden warming of a severely hypothermic person can send the heart into a fatal, irregular beating pattern or arrhythmia.