Brand: Sierra Designs
Model: Mobile Mummy 2-season
Overall Score: 3.8 / 5
Why we like it Never fear the blast of cold air when you get out of your sleeping bag because you never have to get out of your sleeping bag.
Mobility The secret: a two-way center zip that stops about 12 inches short of the bottom, and armholes on each shoulder. Pop your arms out of the self-sealing openings, unzip from the bottom, stick your legs out, and voila!, you’re mobile. Fasten the loops on the bottom of the bag to toggles midway up the bag’s backside to prevent dragging while you go get your coffee. Bonus: Cut pack weight by leaving the puffy at home.
Versatility “I spent six nights in the Grand Canyon with only a ¾-length pad and no tent, and I was thankful for the ventilation options on warm nights,” says one of our park ranger testers. “I just stuck out my arms or popped out a leg. Plus, I loved being able to climb inside before dinner, and then just flop over onto my pad at bedtime.” The 800-fill DriDown performed well on colder nights, too. Testers stayed warm into the low 30s, although a few wished for a drawcord to cinch down the face opening.
Packability It compresses to the size of a 1-liter water bottle if you use an after-market compression sack.
$329; 1 lb. 11 oz.; 30°F; also available in a 15°F version ($379; 2 lbs. 4 oz.); sierradesigns.com