I just got back from my first trip with my clark nx-250 and don't know if I need an under quilt or what... I spent two nights in the hammock with a zero degree mummy bag but both nights my back and bottom of my legs got cold but my chest and top of legs were literaly swetting... So what do I do? I was thinking under quilt but what one is best for clark nx-250? Any and all advice is apprecaited.