"I am nothing more than a single narrow gasping lung, floating over the mists and summits." -Reinhold Messner
From 1960-61, physiological tests were conducted on an expedition team led by Sir Edmund Hillary. These tests concluded that oxygen levels at the summit of Mt. Everest were only enough to support a body at rest. 17 years later, on May 8th, Peter Habeler and Reinhold Messner puzzled the medical community by making the first ascent of Mt. Everest without supplemental oxygen.
Habeler taking a break on Everest
L-R: Habeler and Messner
The documentary "Everest Unmasked" follows Habeler and Messner on their route through the Khumbu icefall into the Wester CWM then up to the South Col and Summit. The film, available on VHS (looks to be out-of-print), was produced and directed by Leo Dickinson.