Yeah, and sun stroke doesn't necessarily hit while you are exercising. I learned that at last year's race weekend. Biking for some 2.5h beside the boyfriend in sweltering heat ( have no clue how HE survived), on a black bike, black helmet, black shirt and black gloves and no sunscreen. By the time he was done and we made our way to a restaurant by body decided to just go bye bye all of a sudden.