The hose is connected to a machine that lowers the air's oxygen content, thereby simulating a mountaintop environment.

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Managers said the special rooms will have small amounts of nitrogen piped into them to reduce the oxygen content in the air, so fires cannot start.

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The researchers did note that many of the cases of lightheadedness could be due to the relatively low oxygen content of cabin air-roughly equal to 8, 000 feet above sea level-or to passengers experiencing dehydration during long or multiple flights.

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Stray-Gundersen worked for the Norwegian Olympic Committee from 1997-2002, sealing bedrooms of the country's top Nordic athletes and adjusting the oxygen and nitrogen content of the air, so they could sleep in a simulated high altitude environment (he was the scientist who developed the concept of living at high altitude to increase hemoglobin levels).

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