His attempt to become the first man to cross both polar caps and climb the world’s highest mountain had been thwarted a few hours short of the summit. He had felt a pain in his chest which, he said, he took to be the onset of a huge heart attack and decided to turn back.

“I wouldn’t like to admit to being scared,” he said. “But I suppose in all honesty you could say that.”

Sir Ranulph, 61, had had a double heart bypass in 2003, and he thanked his doctor and his new wife, Louise, for making him more cautious. “I suppose over 35 years of trips I have learnt to be suspicious of wimpish thoughts due to various parts of your body twingeing,” he said nonchalantly. “This is a danger for people who want to break records. You get used to ignoring that voice in your head.”

Speaking in a Heathrow hotel, he looked tired and gaunt, with hollow, sunburnt cheeks.

The explorer, who also has bronchitis, said that he had suffered mild chest pains on a recent expedition to Kilimanjaro and knew that what was happening to him six hours below the summit of Everest was serious. “I was going up a rock on a fixed rope when it started. It was as if somebody was trying to tear the wire apart which had done up my ribs [after the bypass]. My immediate thought was that I’m going to have a massive heart attack again within seconds. I remembered that Louise had shoved an emergency respirator and some pills into my rucksack. I took about six pills instead of the one that I should have taken.”

He had been tempted to dismiss the pain and push on for the summit because he was “so close”. But if he died he would have been seen as a “silly fool”.

He had to get down to sea level. “The sherpa said that coming up this steep icy mountain at night was possible but going down we would definitely die.”

At dawn they scrambled down to Advanced Base Camp. On Sunday they reached Base Camp and were given safe passage by Maoist rebels. “By the time we got to Kathmandu I was beginning to think I would not kick the bucket.”

He remained confident that he would still achieve his goal of raising £2 million for the British Heart Foundation.

This year he will go up the Zambezi on foot and by canoe to commemorate Livingstone’s discovery of Victoria Falls 150 years ago — the heir to the Victorian explorers paying homage to one of the greatest.

LIFETIME OF ADVENTURE

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