No cause of death was reported.
swelling that he was unable to continue.
Houston, who had begun studying high-altitude physiology, thought it likely that a fatal blood clot would reach his lungs. The healthy members of the team, knowing it would be nearly impossible to save Gilkey, nonetheless wrapped him in his sleeping bag and tent and lowered him down the mountain, inch by inch.
But one man slipped, and the team, tied together, fell. The youngest member of the party anchored his ice ax just in time to save them from certain death. It took an hour for the climbers to recover their ground, and when they reached Gilkey's position he was gone, presumably swept to his death by sliding snow.
Houston wrote movingly of Gilkey's life and death in "K2: The Savage Mountain" (1954), which has become a classic in mountaineering literature, and he carried guilt over the episode for many years.
As a result, Houston (pronounced HOW-stun) gave up mountaineering and devoted himself to the medical dangers faced by climbers. Four years later, while treating a sick skier in Aspen, Colo., Houston was the first to document high-altitude pulmonary edema, a buildup of fluid in the lungs, one of a complex of potentially fatal illnesses that beset alpinists.
A decade later, he was the first to identify high-altitude retinal hemorrhages, which are similar to a condition sometimes found in newborns. In 1975, he launched the Mountain Medicine Symposium, which became the International Hypoxia Symposium, the premier venue for high-altitude medical studies, in which he stayed involved almost to the end of his life.
He also helped found the medical branch of the Peace Corps after serving as the organization's first country director in India.
Charles Snead Houston was born in 1913 in New York and began climbing at age 12, first in the Alps and later in Alaska. He graduated from Harvard College and received a medical degree from Columbia University. While in medical school in 1936, he was a member of the first team to top Nanda Devi in India, then the world's highest ascent. In 1938, he led another climbing party conducting reconnaissance on K2, reaching 26,000 feet before time and food ran out.
During World War II, Houston served in the Navy, doing research and training that helped tens of thousands of U.S. pilots survive low-oxygen conditions to fly above German and Japanese fighters.
After World War II, Houston returned to the Himalayas, blazing most of the trail on the south face of Everest that Sir Edmund Hillary and Tenzing Norgay completed in 1953, the year of Houston's harrowing episode on K2.
Houston practiced internal medicine in Exeter, N.H., Aspen and Burlington.
His wife, Dorcas Tiemeyer Houston, died in 1999.
Survivors include sons Robin of Bozeman, Mont., and David of Burlington; daughter Penny Barron of San Diego; six grandchildren; and two great-granddaughters.
Sullivan writes for the Washington Post.