When your adventures push into the planet's most unforgiving corners, the Marmot CWM -40C sleeping bag delivers the kind of bulletproof warmth that separates epic expeditions from survival stories. Built around premium 800-fill-power RDS-certified goose down and a waterproof Pertex Shield shell, this extreme cold sleeping bag creates an impenetrable fortress against temperatures plummeting to -40C, while still breathing enough to prevent that clammy, claustrophobic feeling that ruins sleep at altitude. The multi-baffle wraparound footbox and adjustable hood system work together to trap every precious calorie of body heat, while dual-side zippers give you the flexibility to vent or bail out quickly when conditions change. Whether you're establishing base camp in the Himalayas, crossing polar ice fields, or pushing your limits on winter mountaineering routes, this expedition sleeping bag transforms the coldest nights into restful recovery time, so you can wake up ready to tackle whatever the mountain throws at you next.
