The purpose of hair?

“Like all other mammals, human beings have hair on their bodies. The chief job of this hair is to retain the body’s heat, so that we do not die of cold. A man grows hair on his face and not so much on the top of his head, while a woman has more hair on her head and far less on her face. Men also grow hair on their chests, which women do not, and the hair on a man’s arms and legs is much thicker than a woman’s. Humans also have fine hair in their ears and noses, and your eyebrows and lashes are, of course, body hair. It is believed that these hairs protect the delicate organs against dust and insects, which could otherwise damage them.”