*Kitty laughs hard* It's not really. It keeps me feeling cooler longer that's all. Kinda like the reason why pigs roll around in the mud. Mud is dirty so that idea is out.

A sheet does insulate better than just having multiple covers, plus if you get too hot, you still have something covering you. Guess since I live in a fairly hot climate I always have a sheet, I like being warm but if I get hot I can't goto sleep. Cold doesn't work too well either, as the one time my roomate decided to keep it close to freezing in the room I woke up with cramps, since I only had a sheet at the time as it was still summer. Sleeping in the fetal position to keep warm is not fun. Needless to say that problem never happened again.

Still don't get the obsession with being overly bundled up. If you get hot take some of it off, geeze. Plus unless it's like below freezing outside there is never a need for more than one blanket. I know I have a fleece blanket (comforter), and it stays pretty warm. Never used 2 blankets.

Also it would seem going to bed wet would lead to mildew or other build up in the sheets, and will just make you feel hot and humid, which is the worst. I know, I live in it. It's pretty humid here all year round (not close to rain forest humid but still pretty sticky). Which also makes it feel colder in the winter as well (well on the weeks of winter it's actually cold here).