Explanation:
Aside from being good for raising, furrowing, and piercing, the hair there keeps the sweat out of your eyes. And the hair on your head shields your noggin from the direct force of the sun. It also leaves an area of air between your scalp and hair's hot surface, so sweat can evaporate and cool things down.
While humans have developed clothing and other means of keeping warm, the hair found on the head serves primarily as a source of heat insulation and cooling (when sweat evaporates from soaked hair) as well as protection from ultra-violet radiation exposure. The function of hair in other locations is debated.
