Can't quite say I'm a ATGATT guy, but pretty close. Mostly from experience. Not only can you get sunburn from riding around in summer clothes, you can get windburn, too. I always wear boots (but then I usually wear at hiking boots at work or home, so that's easy) and full-fingered gloves. I do ride sometimes with jeans instead of riding pants, but NEVER in shorts - if it's hot enough for me to wear shorts, the bike is hot enough to burn me. My Joe Rocket Alter Ego jacket was purchased so I'd have a jacket that I could use year-round. Granted, in it's mesh form it's not gonna be as protective, but it's gonna be better than a t-shirt. Helmet is pretty much a given since the law requires it, but I have been known to ride without one on rare occassion when riding the dirt bike around the back yard (which is done without the jacket) or back when it was legal, a quick little trip down the road to the beach or the store.