If frostbite or hypothermia is suspected begin warming the person slowly. Warm the person's trunk first. Use your own body heat to help. Arms and legs should be warmed last since stimulation of the arms and legs can drive blood to the heart and lead to heart failure. Never give a frostbite or hypothermia victim something with caffeine in it or alcohol.
Caffeine can cause the heart to beat faster and hasten the effects cold has on the body.
Alcohol can slow the heart and also hasten ill effects of cold body temperature. Conserve fuel by keeping your house cooler than normal. Refuel kerosene heaters outside and keep them at least three feet from flammable objects.