Is there any benefit to working out in full sweats?

There are at least 2 or 3 guys wearing full sweats from pants to a hooded sweatshirt WITH the hood on. it's gotta be over 75 degrees in the gym i go to, or at least it feels like it. i'm hot and sweaty wearing shorts and a shirt without sleeves. i can't imagine that these guys are any better off. i don't get it. what's up with this?