Q:
With winter upon us, I am wearing a hat again. Is it true that you lose most of your body heat through your head?
A:
You do not lose most of your heat through your head. The amount of heat lost by your body is largely driven by surface area. If it was a cold day and your head and one leg were exposed, you would lose more heat via your leg than your head because your leg has more surface area. In general, your head accounts for 10% of your body’s surface area and should account for 10% of the heat lost.
How did this myth arise? Cold weather experiments conducted by the US military in the 1950 led to this myth. The military personnel were exposed to cold weather and were clothed in various survival suits from the neck down. The end result was most of their body heat escaped through the body part not clothed.
A body functions best an internal temperature of ~98.6°F and heat loss is normal. The best approach to manage heat loss is wearing an appropriate amount of clothing to help maintain the ~98.6°F. The body gives us signs (sweating, feeling stuffy, shivering, etc.), we should respond to those signs to help our body effectively manage the internal temperature.
The following websites were used as references in answering the question: