Hypothermia: Abnormally low body temperature. Someone who falls asleep in a cold temperature may become hypothermic, and the condition can be fatal. Hypothermia is intentionally produced to slow the metabolism during some types of surgery. Severe hypothermia can be fatal. Those with mild or moderate hypothermia (are alert and conscious, and have not lost the shivering reflex) will usually simply require removing them from the cold environment and providing them with additional insulation. Treatment of severe hypothermia involves slow heating of the body using blankets or other ways of increasing body warmth. Body temperature should increase by no more than a couple of degrees per hour.