When I have camped in cold conditions in a sleeping bag, I couldn't get warm until I totally zipped up my bag and put my head inside; it made a huge difference.
So my question is: to what extent does a separate Top/Bottom underquilt combo leak out warmth and lose the "sleeping bag" effect? How can the top quilt stay "snug" when you toss and turn during the night? I have a Snugpak cocoon-- essentially a giant sleeping bag that the hammock goes through-- and I believe it prevents the escape of body heat very well, the same way a sleeping bag does. But it's heavy. I'm looking at large sleeping bags with foot vents as an option for summer conditions.
I'm arguing that the "peapod" effect greatly increases the warmth of a sleep system, and separating the top and underquilt reduces it, the same way a sleeping bag isn't maximized until it's totally zipped up. Comments?
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