Have you guys watched "So You Think You Can Dance" on TV? The guys often wear nothing on top. Yet they often finish their several minute routines drenched in sweat. Imagine that in a cold ice rink.
Are there rules on what figure skating guys must wear too?
Most of the guys skating finish their routines drenched in sweat too, and many of the ladies. And in shows, they often wear very different outfits than in competition, exposing a lot more skin. (For the record, as a skater, I'm rarely cold while doing a program in competition wearing a sleeveless dress and a single pair of tights. Too much adreniline. The cold exists in warm up (jacket + gloves!) and kicks in afterwards.) To some extent, I think they get used to it. There is a video behind the scenes of the Skating Gymnastic spectacular, and all the skating ladies are in tank tops and yoga pants, all the gymnasts are in parkas with fur hoods.
There are rules on what guys must wear. They have to wear pants, not tights. Since it is described as trousers, I would assume also no shorts. John Kerr had to get special permission to do an ice dance in a kilt, as men can only wear pants. I want to say they cannot be in sleeveless tops, but I couldn't find that in the USFS rulebook on a quick glance. (ETA: Actually the no sleeveless rule appears in the Dance part of the rulebook. It isn't there for singles, but I can't think of any sleeveless costumes in men's singles. And for dance it says 'full length trouser', where singles it just says trouser.)
I find it really outdated that dance ladies cannot wear pants (adult dancers can). Professional ballroom competitions will occasionally have ladies show up in pants, and since free dance isn't really even ballroom, but just dance- there are MANY styles of dance where ladies wear pants. I mean look at the silly skirt Natalie Penchalant (sorry about spelling) had to put on her Mummy costume just so she'd have a skirt.