Early this May, an airline pilot, two entrepreneurs and a government minister will wait for the call to mobilise. The British group’s gear will already be at Everest base camp alongside Lukas Furtenbach, an Austrian mountain guide. As soon as he declares that a weather window is about to open, his clients will dash to Heathrow for the next flights to Kathmandu.

They will then take a taxi straight to a health clinic. For 30 minutes, each adventurer will wear a mask attached to a ventilator for administering xenon, a rare noble gas more often used as an anaesthetic and a rocket propellant.

After inhaling a xenon blend formulated by a German doctor who first presented Furtenbach with the radical idea, the men will fly by helicopter to base camp. After no more than two hours to get ready and meet their half-dozen Sherpas, they will begin their ascent.