To each his own, but I would never ride in anything less than a pair of heavyweight jeans and real riding boots. When I see people riding in shorts and sneakers or flip-flops or similar footwear I assume they are newbies that haven't had their first "git off" yet and haven't learned any better. You have personally found one of the other common problems associated with riding with bare skin exposed. Passengers tended to be the ones that suffered burns from exhaust pipes more than riders back in the day, when guys would give rides to kids or girl friends who weren't regular passengers on bikes. I don't let the wife get on my bike in anything less than jeans, riding boots, gloves, jacket, and a helmet - same stuff I wear. Can it be uncomfortable in 90° weather? Sure it can. Is it more uncomfortable than a second or third degree burn, or a case of road rash? Absolutely not.
JMHO - Jerry
I'm not gonna argue with you. I'm just gonna say Ive been riding since I was eleven years old, and Im 50. I just made a decision to dress for the weather. Seriously, on really hot days I didn't even want to go riding its just too uncomfortable. I am aware of how much it can hurt and for how long. I dont wear helmet unless its cold or the law requires it. I wear what I need to be comfortably functional for the conditions. I'm not out to convince anyone to follow suit.
Flip flops are not gonna happen, that makes no sense at all. I need grip, more than most, Im 5 6, and shifting would suck I imagine.