Warmer and lighter than, well, everything else.
Frankly, ultralight cold-weather bags don't come any lighter than the Marmot Plasma 0-Degree Down Sleeping Bag. If 2.5 pounds seems like a lot to you, just remember that the burrito you ate for lunch yesterday probably weighed more than that, and wouldn't keep you warm nearly as efficiently. The ultralight Plasma's secret, aside from 875-fill goose down, is its vertical Insotect Flow baffle design, which keeps down in place and maximizes the efficiency of the bag, keeping you warmer with less insulation. Of course, down also has to remain dry to function correctly, so both the inside and outside of the rugged Pertex Quantum bag have a DWR coating, and the down itself is treated with Down Defender, the better to maintain loft it does end up slightly soggy.
If you read all that and thought "meh", don't worry, there's more—the Plasma has a wrap-around footbox to minimize weight while maximizing warmth for your toes, and insulated draft tube and collar, and a face muff to stop drafts in their sneaky tracks. Toss in the fact that it compresses down to the size of a baby mouse (approximately) and has hang loops to aid with drying and lofting, and it's easy to see why the Plasma's one of the best bags out there.
- Lower limit rating of 3.2 degrees, suitable for moderate-weather winter camping
- 875-fill down with Down Defender water-resistant treatment
- Mummy bag with Insotect Flow vertical baffles
- 10D Pertex Quantum nylon ripstop fabric
- Drawcord hood with insulated collar and draft tube
- Wrap-around footbox construction
- Two-way zippers with garage
- Hang loops