Hypothermia is defined as a body core temperature below 35.0 °C (95.0 °F). Symptoms depend on the temperature. In mild hypothermia there is shivering and mental confusion. In moderate hypothermia shivering stops and confusion increases. In severe hypothermia there may be paradoxical undressing, in which a person removes his or her clothing, as well as an increased risk of the heart stopping.Hypothermia has two main types of causes. It classically occurs from extreme exposure to cold. It may also occur from any condition that decreases heat production or increases heat loss.Commonly this includes alcohol intoxication but may also include low blood sugar, anorexia, and advanced age, among others.