MOUNTAINEERING -- In a quest to become the oldest man to scale Mount Everest, 82-year-old Shailendra Kumar Upadhyay instead became the oldest man to die climbing the world's highest peak.

According to the Associated Press, the retired Nepalese foreign minister collapsed and died on the slopes of Mount Everest while returning to base camp Monday evening.

High-altitude sickness, a common cause of death among mountain climbers, is thought to be a factor, Nepalese authorities said.

Upadhyay had said he wanted to raise awareness about the capabilities of elderly people by scaling Everest. The Himalayan peak has claimed the lives of hundreds of more youthful mountaineers, including last week's death of a 55-year-old California man seeking to complete the last of his "seven summits" quest.

If he had succeeded, Upadhyay would have become the oldest person to reach the top of Everest, beating current record holder Min Bahadur Sherchan, who scaled the mountain at the age of 76 three years ago.

About 3,000 people have climbed Everest since Edmund Hillary and Tenzing Norgay became the first people to conquer the 29,035-foot  peak in 1953.

May is considered the optimum time for climbing in the Nepal Himalayas and about half a dozen people, most of them Nepalese, have reached the top so far this year.

Hundreds more are on the mountain waiting for the right conditions to launch their attempt on the summit.