I had my 3 Season Incubator & Burrow down to 30 degrees weekend before last and was toasty warm in light weight polypro long sleeve top & long bottoms, light weight smart wool socks, and Black Rock down beanie. No cold spots at all. Minimal adjusting for my first real use of this underquilt. I just shortened up the end shock cords a little bit by tying in a loop, and made sure the end channels were snugged up. I am 5'6" and I had great coverage from head to toe.