I'm in smokepole's and EdT's camp all day long.....
I'd rather get hot than have my balls chattering. Been there done that lots of times. Never again. If you want to carry all sorts of crap to sleep in on a giant mountain and carry it all in and bring a bag rated 20 degrees warmer than what you might experience on a backpack hunt because you don't like to get too hot and don't like to stick your leg out while sleeping then go for it. Not good advice for 95 percent of the folks reading I'd say, nor for me. I at times sleep with base layers, etc when needed but to plan to do that on purpose is not planning properly IMO. If it works for you great.
