Sleeping bag testers learn to be wary of sacks that seem too light to be true. So it was no surprise when our crew greeted this mummy—a tick over two pounds, and as compressible as a summer bag—with skepticism. Few dared take it to its 15°F limit. But the Mountain Light proved them wrong. “I stayed warm right down to its rating,” reports one tester, who camped on snow in Colorado’s Indian Peaks. The impressive warmth-to-weight ratio comes from 800-fill, water-repellent DownTek-treated feathers sandwiched between ultralight, 15-denier Pertex Quantum fabric.
Plus, vertical baffles (which channel body heat from the core to the extremities) help the lightweight materials deliver coal-engine heat. DWR-treated shell fabric repels moisture, even when testers camped tentless. “On an 11,000-foot summit in Wyoming’s Tetons, the dew beaded right off the bag,” says one tester; another found that the treated plumes maintained loft over a soggy, four-day trek in Vermont’s Green Mountains. Six-footers fit comfortably, and called the 60-inch shoulder girth adequate. “It’s perfect for mummy-haters,” one reports, since the bag has a more gradual taper to the foot than most. “I can actually cross my legs.” The pouch near the hood earned rave reviews. “I love having a warm place to put my pocket camera besides the foot of my bag,” one tester says. It’s not cheap, but the price is actually pretty sweet for the warmth-to-weight. $399; 2 lbs. 2 oz.; 15°F; ems.com