Quote Originally Posted by OakLeaf View Post
but if your scalp burns if you go outside without a hat, then it will burn under a well-ventilated helmet too.
I'm in the sun burn without a hat group despite seeming to still have full coverage of hair. (This was an unexpected result of aging! The color got lighter - and gray - and I assume the amount of hair thinned out.) However, I haven't had sun burn problems when wearing a helmet. I think the helmet is thick enough that the openings only pass sunlight from a narrow range of angles. Normal movement while riding keeps changing the angles. Thus any portion of the scalp only gets sunlight a small fraction of the time.