Snow Peak Grand Ofton Double 1600 [Lower Limit Temperature: -15°C] I took it out once at home, but only unfolded it; I haven't slept in it or used it outdoors. It's almost unused, but please refrain from purchasing if you are concerned. Breaking away from the preconceived notion of "camping = sleeping bag," this product achieves unprecedented sleeping comfort. By sleeping directly on the mat, the down from the futon is generously used in the comforter, a new concept. The ability to create gaps by shifting it when it's hot is also a good feature of Japanese futons.