Last night I built a new hammock stand because I have no trees in my yard. I wanted to try out my new underquilt because the temp was going to get down to fourty degrees, which would be the coldest temp I've hung in. I got the underquilt to fit nicely and just used a thirty degree sleeping bag as a top quilt. My problem was that throughout the night I would randomly wake up with the chills. At the same time though I could definitely feel the warmth from below. So I'm assuming I was getting chilled from above. What do you guys think? The temp is supposed be the same tonight so I want to change some things and try again. Could the answer be as simple as a stocking cap?

Weather: light rain
Temp: 40 degrees
Wind: 15 mph

Hammock: WBBB 1.1 double
Tarp: superfly with doors closed
Underquilt: hg incubator 20 degree
Sleeping bag: 30 degree eureka (syn)