We need to allow for this by using breathable fabrics to allow this moisture to pass out freely. Heat lost from inhaling cold air and exhaling warm air. Impairs the ability to reason, so the victim may not react properly. Increase fluid intake at first signs of darker yellow urine. Mild cases - drink liquids, keep warm.
More severe cases require professional medical treatment.
Hypothermia Lowering of the inner core temperature of the body. Can and usually does happen above freezing. The victim may not recognize the symptoms and may not be able to think clearly enough to react. Injury or death may result. Poor physical condition.