The most efficient mummy bags are narrow in the torso and taper from there. That's good for trapping heat, and good for smaller hikers and sleepers who lie still. If that's you, crawl in this bag and say goodnight. "It's wonderfully warm for the barely-there weight," said one veteran tester after using the Ultralite in a wind-raked camp below Mt. Whitney's East Face.
The trim cut (59-inch shoulder girth) and overlapping draft tubes prevent cold spots even in stiff breezes. It packs down to melon-size thanks to premium 850-fill down and ultralight 20-denier nylon fabric. Bonus: It comes in a small, so height-challenged ounce-counters (under 5'4") don't have to haul extra weight. $385; 1 lb. 13 oz.; 20°F