We lose most of our heat through our heads – but right?

“Put on a hat, otherwise you'll get sick!” We often heard this saying from our parents, because the rumor has persisted for a long time that most of the body's heat disappears through the head. But is this actually true?

This alleged fact is based on an older study by the US Army, which apparently proves that as much as 40-45% of body heat is lost through the head. At that time, the US Army exposed some soldiers, who were equipped with arctic survival suits but without headgear, to polar temperatures. The experiment showed that the test subjects absorbed a lot of body heat through their heads. The fact is that this is the only way body heat can escape from a completely insulated body. This study was therefore carried out under conditions that were not entirely ideal, as we now know.

But what's behind the rumor? Is more heat lost through the head than through other parts of the body with the same surface area? Hypothermia experts from the University of Louisville say no! Other parts of the body radiate heat equally, but since the head and face are usually uncovered, we usually lose a disproportionate amount of heat there. It should also be noted that the head has more nerve receptors, which react faster when we get cold. These help us to feel the warming hat more strongly.
In fact, most of the heat is given off by the limbs that are furthest away from the torso, i.e. fingers and toes. But since these are mostly covered, heat loss is not really noticeable.

Especially when doing outdoor sports in winter, care should be taken to ensure that the body is covered as much as possible in order to keep heat loss as low as possible and to prevent severe freezing and illness. So, put on your hat and gloves and head outside!