All right, my first thread was an introduction, now down to business.

It seems like it can be 30 degrees F (last night) or 60, and invariably, I'll wake up several times in the night with a cold back. This happened last night in a dome tent with the fly on, on a full size air mattress, inside two warm-weather sleeping bags (one inside the other), with a light fleece blanket on top of me (inside the bags), wearing a set of thermal underwear, polyester blend socks, pajama pants, a thick sweater, and a wool hat. Sleeping on my stomach, back, or side didn't seem to make any difference.

I wasn't discernibly sweaty at all, but I must be doing something wrong. How do I keep my back warm?