I am hoping that someone can help me with condensation problems under my sleeping bag and above the pad.
I was camping this weekend with temperatures in the middle teens overnight and a bit of wind all night long, Not real hard winds but enough to keep a flag flapping to not fully extended. I had my tent pitched so the wind was at my head and one flap of the vestibule on each side of the tent half unzipped and the inner doors of the tent open and tied back. My sleeping bag is a cheaper Colman bag and I use a thermarest pad. I never felt overly hot, but in the morning there was frost/ ice flakes on inside of the tent fly which I expected, but the underside of the sleeping bag was soaked with a large amount of what I assume was my sweat. How does one prevent this? I never felt like I was to warm, a few times I woke up with cool feet from cramming them down by the zipper past the draft tube. And arms that came out of the bag got a bit cool until they were pulled back in the bag. The good news I guess is that I was warm and the bag did wick everything away from me.
Thanks
RDL

You may need to try a vapor barrier when it's below freezing. I'll bet there was condensation on the inside of the outer shell of your sleeping bag on top, probably frozen. Below you it was warm enough that it went into the space between your bag and the pad.

Not everyone is comfortable with a vapor barrier (which you use over a wicking base layer), but it sure helps me stay warmer and have a dry sleeping bag in the morning! You'll have to try it to see if it helps you.

I agree half way with Mouse. If you put a vapor barrier on top of the floor of your tent, under your gear pads and bag, like thin painting plastic, the floor of your tent will be much dryer, try it and report back please because no one will believe me.
Jim

The floor of the tent was dry to the touch. All of the moisture was between the bag and the Pad and a nice little chunk of ice/moisture right at te top of the bag were I think I was breathing on it most of the night.

Rdljr
Well then I take back what I said. The only time I ever saw something like that was when a friend used a zrester only on a winter trip and the little waffle patterns had water in them. So I'd change my comment to "you aren't using enough insulation under you". I'm also wondering if you could have rolled over onto moisture blown into the tent or if you got the top of your bag wet and then rolled over with it? Also it is very unusual to get frost inside a tent with the door open into the wind, sounds like there might have been a heavy dew as the temps dropped.
Jim