Our cold-sleeping tester saw temps in the mid-teens in the Tetons, and she was worried she’d freeze. “But I was so warm, I didn’t even need to heat a water bottle to cuddle up to.” Sewing the pad directly to the bag creates a closed system that maximizes heat retention (less of the warmth in your bag is lost due to cold spots, slipping off your mat during the night, etc.). Also, the 3.5-inch-thick pad’s synthetic insulation makes this suitable for year-round conditions, as validated by some of our editors who slept directly on the snow in British Columbia. But we recommend you make sure the pad fits you before you buy: The Airbender only comes in one size, and some testers were chilled when their heads and/or feet hung off the 70.5-inch mat.
Integrating the pad and bag shaves weight by removing almost the entire bottom third of traditional fill and materials. “Typically the total weight of a bag this warm and an insulated pad would be upward of 3.5 pounds, and that’s if you’re combining already lightweight products,” says one of our more experienced testers. Thank the featherweight ingredients: 850-fill, DownTek-treated goose down, small amounts of ClimaShield HL synthetic to boost moisture resistance in key areas, and a 15-denier Pertex Quantum shell. It shrinks to 8 by 12 inches with the included compression sack (which doubles as an air pump).
We tested this bag for nearly a year and didn’t have any issues with sticky zippers, leaky mats, or torn shells. Bummer: Innovation like this ain’t cheap.