Why Must Climbers Wear Oxygen Masks at High Elevations?

Why Must Climbers Wear Oxygen Masks at High Elevations?
Watch videos of Mt. Everest ascents and you will notice that climbers wear oxygen masks on the push to the summit. Oxygen not only makes a climb physically easier, it also can serve as a life-saving piece of gear.

Thin Air

At high elevations, low air pressure makes the air "thin." In other words, there's less oxygen available to breath in any given space.

Decreased Consciousness

Without oxygen masks, acute mountain sickness can cause decreased consciousness, interfering with judgment.


Acute mountain sickness causes lethargy and shortness of breath. Decreased physical ability hinders safe and timely mountain travel.


High-altitude pulmonary edema (HAPE) is a life-threatening condition resulting in fluid buildup in the lungs. Lack of oxygen at high elevation can cause HAPE.


High-altitude cerebral edema (HACE) is a potentially fatal condition where fluid builds up in the brain as a result of oxygen deficiency.

Article Written By Kathrine Cole

Kathrine Cole is a professional outdoor educator. She teaches rock climbing, backpacking, cycling, and bike maintenance classes. She is a graduate of the National Outdoor Leadership School, a Wilderness First Responder, and a Leave No Trace Trainer.

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