Okay…I have been wondering this for years. What the heck causes many bicycle riders to get an oblong-shaped reddish spot on their forehead from their bike helmet. It’s not like there is something on the inside of the helmet that is shaped in that manner, nor do I even wear my helmet tight enough where a spot should be caused by pressure. I have had this happen with several types of helmets too, so it is not necessarily a brand-centered phenomenon. Could it be as simple as I am not wearing my helmet correctly?
So, what the heck causes this spot to form nearly every time I ride my bike? It disappears within 5-10 minutes of taking off my helmet. I know this question is of Earth-shattering importance, but any thoughts, hypotheses, and educated guesses are welcome. Thanks!