Slim mummy bags are great for their thermal efficiency, but if you’re tall, wide, or both, you might want something with a little more elbowroom. Big guys loved this spacious, semi-rectangular, 650-fill down bag, which still packs reasonably small despite its increased internal dimensions. Our 6’2”, broad-shouldered tester raved about the extra room in the ever-so-slightly tapered footbox: “There was adequate kicking room so I didn’t feel like King Tut.” And he loved the option to vent the bottom of the bag and lay the hood fully flat for mild nights.
The self-described “very, very warm sleeper” appreciated this extended-temperature-range versatility on several 55°F nights in Channel Islands National Park, where he slept “comfortably without waking up in a pool of sweat.” You can even use the wrap-around zipper to open the bag fully and use it like a blanket for cabin camping. The 2D Permashell fabric, a 33-denier nylon with DWR finish, breathed extremely well on both steamy and chilly nights. “It did a magnificent job at keeping me nice and cozy down to 22°F,” said one warm-sleeping tester after a trip in Joshua Tree National Park. “I usually end up feeling clammy sometime around 2 a.m., but this bag breathed so well that I stayed dry.” That helps the down stay dry as well, preserving loft.
Downside: Due to the Trek’s semi-rectangular cut, it’s slightly heavier and a bit bulkier than other bags in its class (11 x 9 inches in its included compression sack), but for bigger-framed folks, it’s a worthy tradeoff. $289; 2 lbs. 11 oz.; 12°F; seatosummit.comIf you require a sub-freezing warmth sleeping bag in the smallest possible size, the McIII is your bag.