Narrator: This is Science Today. If you've ever traveled to elevations of eight thousand feet or higher, you may have experienced altitude sickness. John West, a professor of medicine and physiology at the University of California, San Diego, says the body stores of oxygen are very small, so if a person is deprived of oxygen, symptoms including shortness of breath, fatigue and trouble sleeping set in.

West: It's not that the oxygen concentration decreases, but the total pressure decreases and therefore, the partial pressure of oxygen falls. And so the body just does not function as well.

Narrator: Because miners and astronomers are beginning to work more at high altitudes, West and his colleagues have developed a way to feed oxygen-enriched air into the workers' rooms using an inexpensive, rugged oxygen concentrator.

West: Now they've found that it's enormously valuable. Their efficiency is greatly increased; the level of fatigue is very much less. They can do much more physical work; they can sleep reasonably well, whereas they certainly couldn't before. And so it's the difference between night and day working at that high altitude.

Narrator: For Science Today, I'm Larissa Branin.