Originally Posted by funbun
The entire underquilt doesn't compress, just the one spot on the hip. Go setup your hammock with the underquilt with as much tension as possible. The spot under your hip will compress slightly, enough to make a cold spot.
Just go try it and see. Trying to explain it here won't do much good. It's like one of those weird things you used see on Mr. Wizard's World.
I don't have an underquilt.