Reviewed by David - 26th Jan, 2019 Fail Listed as a comfort rating -1oC. With a limit of -6. I've been using this in conjunction with £50 thermerest liner and merino long John's at temperatures of around -1. Still, my upper body is cold resulting in no sleep. How they possibly mark this as -24oF extreme is beyond me. I even checked to make sure they hadn't sold me the wrong product This is the 2nd product failure from Go Outdoors on this trip, I won't be using this store any more.