Copyright ERS Journals Ltd 1997 European Respiratory Journal

versary Expedition", presented in this issue of the Jour-nal, reports fascinating new data recorded at extreme altitudes (up to 8,000 m) on Mount Everest. Among the interesting findings, was the fact that, on the South Col (altitude 8000 m), alveolar oxygen tension (PA,O2) (mea-sured with a fuel cell) was about 5.1 kPa (38 torr) and arterial oxygen saturation (Sa,O2) (measured with a pulse oximeter) was about 70%, emphasizing the extraord-inary degree of hypoxaemia experienced by climbers at extreme altitudes. The results of the British 40th Anni-versary Expedition agree remarkably well with thos