Find the closest surplus store or hit Ebay , and look for the new military 3 piece sleep system! Best sleeping system I’ve ever used!! ..... and I’ve used hundreds!! Has green “light weight” bag, which snaps into the black “ cold weather” bag, which then snaps into the Gortex “outer” bag. I’ve slept.....no kidding, ON a snowdrift ..... on top of a mountain, outside Bardefuuss, Norway for days on end.