Head, Neck, and Trunk are Tops

“Head, hands, and feet”? Forget that.

Head, neck, and trunk: Keep those warm. Your trunk goes from your shoulders to your hips and does not include arms or legs. Vital organs must stay warm or you die. If they’re warm, the rest of you will be closer to warm.

The head is said to lose 10 to 40 percent of the heat the whole body loses. The surface area of an adult head is about one tenth of the whole body’s skin. Small children have small bodies but their heads are not so small, so for children maybe 20% of heat loss is through the head. But the highest figure, forty percent, may be explainable because from our mouth and nose we lose a lot of warm air from our lungs, and we lose about half our water that way, too, as humidity, and also because fat insulates but very little fat is in the head.

We’ve learned since we froze as toddlers that head, hands, and feet needed the most protection. They feel the coldest, so they must need it the most. And what feels the coldest are face, hands, and feet, or face, fingers, and toes, so we bundle those up like we’re in a hospital.

But what actually is happening is that the skin is sensitive and feels the icy blast, maybe even tingles. The skin should be sensitive; it’s protecting us; nothing wrong with that. However, what it’s protecting are your inner organs, some of which critically depend on warm temperatures, but don’t have as many cold-sensing nerves as your skin has. You depend on your skin to tell you when things are getting dangerous. So, feet and hands are important. They need some protection. But we exaggerate how much. If we protect the head, neck, and trunk, the blood there will be warm enough to protect inner organs, like our brain and our lungs, and more warm blood will circulate to our skin, and help our fingers, toes, and face. That’s why gloves are usually as good as mittens and why we don’t need long underwear, for example.

A jacket with an insulated hood is the main thing you need.