How Down Gear Keeps You Alive on an Expedition
At the Mount Everest summit, your gear has one job: to stop your body heat from escaping. Understanding the physics of insulation is the key to choosing the right gear for your Mount Everest expedition.
Insulation works by trapping 'dead air'. High-fill-power down (800+) is the best material on earth for this. It creates a thick barrier that protects Mount Everest summit climbers from the -40°C air during their expedition.
Any point where insulation is compressed—like your shoulders under backpack straps—becomes a 'cold bridge'. Professional Everest trekking gear uses box-wall construction to ensure uniform warmth during the climb.
While great for Everest trekking in lower valleys, synthetics can't match the warmth-to-weight ratio of down. On the Mount Everest summit ridge, you need the maximum insulation for the minimum weight to preserve your energy.
Don't skimp on your down suit or sleeping bag. In the world of the Mount Everest summit, the quality of your insulation is your primary life support system on any expedition.