THIRTY-ONE years ago this morning, Dougal Haston rose from the highest bivouac man had ever made, the first Scot to reach the summit of Mount Everest.

He and Doug Scott spent a freezing night at 28,750 feet, after reaching the summit at 6pm the night before, having done so via the previously unclimbed southwest face.

The descent, after 33 days on the mountain, was a battle for their lives. Exhausted and overtaken by darkness, they were forced to bivouac: out of oxygen, with no food or sleeping bags, and just a few sips of warm water from their stove. They spent the night warming one another's extremities, and rousing one another from the final terminal sleep.

In a grey dawn they emerged, having neither eaten or slept for 30 hours. As they began their descent, they were passed by another group from their party, making a further summit assault. Cameraman Mike Burke lost his life.

Yet Haston regarded this as less than his greatest feat, behind his first ascent of the south-west wall of Annapurna, pictured above, and especially his winter first, the direct route on the north wall of the Eiger. On the latter he carried on after one of the group, American John Harlin, fell to his death.

Haston spent a sodden night in a storm with one leg on the rock and ice face and the other dangling in the void, in a sling. As day broke, he led the survivors to the summit. At one stage he climbed a 60degree water-ice slope without axe or hammer. It is regarded as one of the most remarkable climbs.

Colleague Sigi Hupfauer recounts in Jeff Connor's biography of Haston: The Philosophy of Risk, how the Scot did it: "My main worry was losing my fingers. My face and eyebrows were frozen, and I couldn't see 20 metres ahead . . . going for the summit the ropes froze into the ice and snow, and we couldn't use them. We were using short bits of rope, or just climbing solo."

Only Hupfauer came off the mountain without serious consequences. Of three Germans, one lost a big toe and the others had all their toes amputated. Another was so traumatised he retired and became a Jehovah's Witness.

Haston and the expedition leader, Chris Bonington, shared recovery time in a hyperbaric chamber, which saved their fingers and toes as they plotted the future Everest assault.

Its success was to bring a CBE for expedition leader Bonington, who reached the summit himself at the age of 51, but there was no honour for Haston. He had killed a young climber and injured two others in a Glencoe drinkdriving incident. Ironically their hero was Dougal Haston. He was imprisoned for 60 days. Even Edinburgh later denied a civic reception.

Yet Haston became a mountaineering rock star, so single-minded that even his parents often did not know where he was. While he was on the Eiger, his mother went into an Edinburgh climbing shop where he worked, asking if anyone had seen her son.

Haston, an inaugural inductee to the Scottish Sport Hall of Fame, died in 1977. He was avalanched while skiing, and was choked to death by his scarf at the age of 37. There is a memorial plaque on the Currie railway viaduct where he climbed as a boy.