Inglis on his way down Everest, by yak

Mark Inglis successfully summited Everest despite suffering mild frostbite and breaking one of his artificial legs.

Phil Doole is not surprised his climbing buddy Mark Inglis has scaled Mt Everest with two artificial legs.

"We lost our feet, but we didn't lose our knees - we're still pretty mobile," he said. "Good on him."

Doole knows better than anyone the pain Inglis endured on his way to the world's highest peak. In 1982, the pair lost their legs below the knees after being trapped in a Mt Cook ice cave by a blizzard for two weeks.

Doole also still climbs and has since reached the peak of Mt Cook.

Inglis conquered Mt Everest on Monday.

Cold and weary, he was last night making his way to advanced base camp at 6400m altitude, his fingers suffering from mild frostbite and his leg stumps bruised and swollen after 40 days on the mountain.

"He's relieved, relieved that he's done it," his wife Anne said from their Hanmer Springs home last night.

"It was just so cold and so dangerous at the top they just turned away and came back down straight away. They were very aware of that small window of time to get back down."

Now the mountain had been conquered, Mrs Inglis said her husband was taking it easy for the descent.

"He's going back down in a sled and then going to ride a yak for the last part of the way because of the bruising on the stumps."

She said he was two days away from base camp, at 5000m altitude, and maybe three days from getting his voice back. The freezing conditions had robbed him of his voice for much of the ascent. He was barely audible as he described to his wife the final push to the summit as "bloody cold, bloody hard".

Mrs Inglis said he planned to stay in Kathmandu for a few days to recover, and she hopes to join him there on Friday. They plan to return to New Zealand next week.

Climbing partner Wayne Alexander, one of four New Zealanders to join Inglis on top of the world, said he was in awe of what Inglis had done.

"What Mark did was just absolutely remarkable," he told Close Up via satellite phone.

"I've never seen such human endurance ... through quite technical climbing and very, very cold temperatures. And he did it so well and so fast. It was a bit like chasing a greyhound."

The Prime Minister said she hoped to congratulate Inglis personally for his "absolutely incredible feat".

"As a very amateur climber myself with two sound legs, and having got to 6000m, I can appreciate what an amazing achievement this is."

Asked whether she would like to scale the world's highest mountain, Helen Clark said: "No, not even with two sound legs. No, it's too tough."

Sir Edmund Hillary yesterday hailed Inglis' achievement as "a remarkable effort".

"I have to admit that I admire his considerable effort ... He's done a pretty good job," said the 86-year-old.