Is most body heat lost through the head on cold winter days? No, not unless you’re bundled up without wearing a hat! You will lose the most heat through the largest area of the body that is uncovered. For example, if you’re wearing a winter hat, a jacket, and shorts, you will lose most heat through your legs. Therefore, you could lose a relatively large amount of your heat through your head, but generally not any more than you would on other uncovered parts of the body.
Losing heat through your head is a rumor that started due to a military experiment that exposed subjects to the cold elements in survival suits that did not have headgear. Naturally, most of their body heat did escape from their head, but this is only because their head was exposed while the rest of their body was adequately covered to prevent heat loss.
This rumor is perpetuated through confirmation bias, where a person might feel as though they’re colder from having their head uncovered, but this is only because they think that this myth is true. In reality, they would be just as cold if another part of the body was uncovered instead of their head, such as their hands or feet.
The body loses heat in a few ways, most of which you’ve probably heard of in science class: evaporation, radiation, conduction, and convection. Evaporation typically doesn’t apply in cold conditions, as it relates to sweating. Let’s look at the three other causes below:
Essentially, radiation causes heat to flow from the exposed parts of the head on all sides, convection causes heat to rise off the body, and conduction causes heat to transfer between the head and anything touching, such as clothing. Conduction releases heat slower due to the insulating properties of various types of headwear.
Since hats cover up parts of the skin that would otherwise radiate heat, a quality piece of headwear will make a big difference in your comfort levels.
Helmet and trapper hats have a thick fabric over the head that comes down on both sides like dog ears. These are typically made of thick material and can cover the ears without much hearing impairment.
Puffer scarves and handkerchiefs wrap around the head in the typical handkerchief fashion, but they provide an extra thick layer to add some distance between the cold air and your warm head.
Beanies are a go-to. They’re so simple and cheap. They’re wildly popular, meaning you’ll be able to find a style and fabric perfect for your use case.
Hoods and balaclavas are similar and very effective. They both wrap around the head to cover the ears and neck, and the balaclava (ski mask) keeps the face warm as well.
While you don’t lose most of your heat through your head automatically, going without a head covering in cold weather can not only be uncomfortable, but even dangerous. Sensitive areas of the face such as the nose and cheeks can be windburnt and ears can even be frostbitten from intense cold without covering. A hat is just as important as any other piece of clothing out in the cold.