Cross a super-warm bag and a weatherproof bivy and you get the Wraith,” says one tester. “The shell on this 800-fill bag was a lifesaver,” said another after spending five weeks on Denali. “It was impervious to the rain-snow mix I subjected it to while sleeping outside my tent, but it dried quickly once I returned to shelter.” Credit Mountain Hardwear’s waterproof and windproof Dry.Q shell fabric, which employs a membrane with superior breathability. The Wraith also has a “hidden baffle” design—a mesh bag-within-the-bag acts as baffle anchor points.
This eliminates top seams (potential cold spots) in the outer shell; our tester stayed toasty down to -20°F. The bag earned praise for livability, even from a claustrophobic tester. Downsides: After 35 days of continuous use, one tester noticed a slight reduction in loft, and the zipper caught routinely on the fat draft tube. Also, it’s on the heavy—and pricey—side. $760; 4 lbs. 15 oz.; reg. and long; mountainhardwear.com
Passive collar: unique design provides the insulation of a collar without a drawcord on the collar. Available in NanoSphere by Schoeller and in Pertex Endurance