Two years ago, the largest ever Swiss high altitude research expedition set off to the 7,546 metre high Muztagh Ata in west China. The aim of the expedition was to learn more about high altitude acclimatisation and the phenomena of high altitude sickness. 36 test persons were examined by medical experts up to a height of 7,000 metres. The results of this research clearly show that the high altitude has more significant impacts on the human body than ever presumed. One can easily risk one’s life if one doesn’t keep to important behaviour rules and early warning signs. In this documentary the scientists for the first time present their surprising results.