Hypothermia- an abnormally low body temperature. It general cooling of entire body the inner core of the body is chilled, so that the body cannot generate heat to stay warm. The condition usually occurs from immersion in cold water but may be produced by exposure to extremely low air temperatures between thirty and fifty degrees F accompanied by wind and rain. Also contributing to hypothermia are fatigue, hunger, and poor physical condition.

Exposure begins when the body loses heat faster than it can produced. When the body is chilled, it passes through several stage :- the urge to move about and exercise in order to stay warm; shivering as an involuntary effort by the body to preserve normal temperature in the vital organs; deprivations of judgment and reasoning powers: feelings of apathy, listlessness,indifference and sleepiness, a loss of muscle coordination.

Cooling become rapid as the internal body temperature is lowered, eventually hypothermia will cause coma and death.