As the cold winter months approach, many of us have heard the age-old advice to “keep your head covered” to prevent heat loss. But is this notion actually true? Michael Okonkwo, a journalist for The Update Desk, investigates the science behind this commonly held belief.
The idea that we lose a significant amount of body heat through our heads originates from a 1970s US Army Survival Manual, which claimed that up to 45% of body heat can be lost from an unprotected head. However, according to John Tregoning, a professor of vaccine immunology at Imperial College London, this is a common myth.
“The reality is that there is nothing special about your head,” Tregoning explains. “When you go out in the cold, you lose more body heat from any area you leave exposed than from those parts protected by clothing.” This means that if you venture out in the cold without a hat, you will indeed lose heat quickly from your face and head, just as you would if you went out without a jumper on.
Interestingly, the amount of heat lost from the head may actually be less than other exposed areas. Tregoning points to a 2008 British Medical Journal article that suggests the head is slightly less naturally insulated than the rest of the body, as it has less fat. The article also argues that vasoconstriction, the narrowing of blood vessels to conserve heat, is less effective on the head.
“Overall, the head does lose heat, but it’s not uniquely heat-losing,” Tregoning says. “There’s a study where researchers put people’s heads in cold water, and then looked at the speed of cooling down, and it wasn’t particularly faster than anywhere else.”
However, Tregoning still recommends covering your face as well as your head in very cold conditions, as you can lose quite a lot of heat through your face. “People probably need to cover their face as well, if they can. You lose quite a lot of heat through your face.”
So, while the notion that you lose most of your body heat through your head may be a myth, it’s still a good idea to wear a hat and cover your face when venturing out in the cold. Staying warm and protected is the key to keeping comfortable and healthy during the winter months.
