Two other medical conditions can affect climbers at high elevations.
Conifers are ancient plants, which evolved to withstand the wind, intense light and poor soil of high elevations.
Warmer than usual temperatures on land and offshore in the North Pacific led to rainfall events even at high elevations.
Smoke also drifted at high elevations over London, said Eddy Carroll, a forecaster at Britain's national weather forecasting office.
The creatures that survive are those on the edge, at high elevations or otherwise isolated in pockets.
Trees that grow at high elevations are adapted to this environment.
Vicuñas are still found at very high elevations, usually above 14,000 feet, in Peru.
He wrote numerous papers on atmospheric electricity, waterspouts, and the boiling point at high elevations.
They give way at high elevations to trees such as Pacific silver firs and mountain hemlocks.
Some of the Ruwenzori Mountains are permanently snow-capped, and glaciers exist at high elevations.
At high elevations, the Kyrgyz exhibit much greater longevity and lower infant mortality than the Tajiks.
