According to Rolf Saeterdal, altitude consultant for the Norwegian Olympic Committee, "Many of Scandinavia's top endurance athletes—runners, cyclists, rowers, cross-country skiers—are using this technology. The Finns have an entire 'nitrogen hotel' where their endurance athletes live. Oxygen is the key element in endurance sports. Controlling it, in both the living and training of athletes, is the future of elite aerobic athletics."

But are oxygen-deprivation chambers part of the future of high-altitude mountaineering, notwithstanding my own obviously flawed experiment?

"It's not the increase in the number of red blood cells that's important to a mountaineer," says Hackett, "but rather the pressure of oxygen in these red blood cells, which is a function of breathing harder. Still, it's likely that sleeping or living in a nitrogen chamber for an extended period before going to high altitude will decrease the amount of time it takes to acclimatize in the mountains."

Levine is more circumspect. "If you think of altitude as medicine," he says, "when it comes to preacclimatizing for mountains in a nitrogen chamber, we don't yet know what the dose should be or how long it should be administered.

"What determines success or even survival on a mountain usually isn't speed," continues Levine. "More often it comes down to good judgment, experience, and common sense—none of which you acquire in a chamber. And given the option of sleeping in a chamber or climbing in the Alps to preacclimatize, well, which one would you choose?"