I think for the first time, I have to think about this. We have a dress code at work: shirts must have collars, trousers must be long, no sandals for men. It's not terribly restrictive or repressive, but my route is 13 or 14 miles long, and I don't want to wear long pants in the dead of the heat. The only place I can find to change my outfit is the handicapped stall in the men's room. I guess I'll make do with that. Normally, I don't mind getting hot and sweaty, and I can cool off well enough without a shower. It's the length of the commute that makes it difficult. I've already ridden on a couple of warm days, and it's uncomfortable, and I haven't ridden this route on seriously hot days yet.