Trapped air acts as a body insulator and allows the body to retain its heat. Wear wool sweaters, long underwear and gloves. Cover the head and ears with a hat or scarf since much heat-carrying blood flows through the many blood vessels of the scalp and ears and an uncovered head radiates heat rapidly. Body heat is lost through damp clothing by evaporation. Drink warm liquids and eat.
Food is the fuel for the body.
Do not drink alcoholic beverages since alcohol tends to dilate blood vessels, increasing the flow of blood to the skin and thereby losing internal body heat.