I believe riders can wear what they want, it's their life, but I won't ride with anyone on a sportbike unless they have at least a jacket and helmet combo. I myself on hot days wear my JR speedmaster leather jacket, jeans, riding boots, gloves, and full face helmet. My jacket has zipper vents and I don't cruise around town if it's a hot day. I'm always moving and out in the country side. My moto is, sweat wipes off, road rash doesn't. I also, am out to ride and not to impress people with how dry I can stay, so I don't care how sweaty I get honestly. They can kiss my ass if they think I look hot, that's my problem, not theirs. Sweating is good for you anyway...just stay hydrated...gatorade and water on those 90+ degree days.