Is xenon breathing life into mountaineering?

CLIMBING MOUNT EVEREST typically takes weeks, with most of that time spent at the foot of the mountain adjusting to the thin air.

- JONATHAN WOLFE & BHADRA SHARMA

But four British men last week shrank that timeline dramatically, traveling from London to the summit and back in less than a week, according to the organizer of their expedition.

They skipped the adjustment period, in part, by inhaling a secret weapon: xenon gas.

Their feat has roiled the world of mountaineering and prompted an investigation by the Nepalese government, as use of the gas is fiercely debated.

Some research has shown that xenon can quickly acclimatize people to high altitudes, even as some experts say the benefits, if any, are negligible and the side effects of its use remain unclear.