I will add that one of the biggest factor in staying warm is a good stocking cap that stays on. Keeping that heat from escaping from the top of your head makes a huge difference.
This x 1000. If your dome-piece gets cold, good luck staying warm.
Tanner
Notice I said "stays on".. (grin) I had one beanie on a hunt that would work it's way off during the night. Wake up freezing cold, find it, put it back on, and be warm again in 10 minutes. I know they supposedly debunked the myth of heat escaping through your head, but every experience I have had either cold weather camping or winter fishing has told me to keep my head covered with a beanie.
No doubt, they like to come off in a mummy bag often! I've taken to either using a beanie with strings that'll tie under the chin or putting a hood on over the beanie as an extra layer. Seems to work well.
