Not to mention, when it's cold its the best first step to keeping warm. 90% of your heat loss is through the top of your head.
So they say, but that's why I was asking; I never noticed all that much warmth or shade from them myself. I am lucky to have thick enough hair that my scalp doesn't burn easily, so that's not a factor for me either.
Ah well, time to go see if I can make them Mikuni carbon-nators work.