Abstract
On 8 May 1978 Reinhold Messner and Peter Habeler became the first to climb Mount Everest (8 848) without supplemental oxygen. They demonstrated unique evidence of human abilities to overcome extremely unfavourable climatic conditions of the highest point of our planet.
Presumption for this barrier-breaking undertaking from the physiological point of view was on one hand above standard cardiorespiratory capacity on the other hand high level of hypoxic ventilátory response. However, the altitudes above 7 500 m are still considered co called death (or lethal) zones, where sojourn or movement without supplemental oxygen is always 8000 m without oxygen remain reserved to only exceptionally fit and experienced climbers.
Messner and Habeler certainly disproved the scientific belief that it was impossible for humans to survive without oxygen in altitudes above 8 500 meters. 8 May 1978 will remain as a historic landmark climb that forever shaped the face of mountaineering.