Ranulph Fiennes is setting off on his next challenge: 'Retirement holds no allure for me'

The explorer Sir Ranulph Fiennes is now 71 and has announced he is ready for his next big challenge, though it is... a secret.

It might well involve extreme heat. And a lot of running. Possibly yet another heart attack. Although known for his exploration of the poles, last year Fiennes ran the Marathon des Sables (it translates, loosely, as “suicidal slog in the Sahara”), becoming the oldest Briton to complete it.

The last stage was almost 60 miles and he ran for 30 hours after just one hour’s sleep in blistering 122F (50C) heat. You’d think at his age he might pack it in.

But Fiennes is unstoppable and quite possibly, like many explorers, more than a bit mad.

He is truly the last of the gentleman adventurers. His record is unique.

He has led 30 major expeditions to the furthest reaches of the globe. He was the first man to achieve the surface polar circumnavigation of the Earth. He was the first explorer to cross the Antarctic continent unsupported, the longest polar journey in history. A few years ago, at 65, Fiennes became the oldest Briton to climb Everest.

He has climbed the Eiger and run seven marathons on seven continents in seven days. You wonder if he ever finds the time to use his bus pass.

The cost? He has survived two heart attacks, undergone a double heart bypass and cancer surgery. He puts up with diabetes and has coped with the loss of his first wife, Virginia, to cancer after 34 years of marriage. (He’s happily remarried.) And he’s no doubt a terrible big head.

According to his own website, and the Guinness Book Of Records, he is the world’s greatest living explorer. You don’t get to become that by being sheepish. Some of this has been in search of glory or the thrill of adventure. But he is also propelled by a passion for raising money for charity. He has clocked up an estimated £16million so far – a staggering sum.

Fiennes is like a figure from a John Buchan novel – the sporting gent and ex-army officer who is easily bored. He is made of leather. What’s left of him, that is.

You can always tell a hard-core explorer by the lack of toes and fingers. Fiennes is way short of the full picnic set. He is old school when it comes to running repairs.

When the tops of his fingers went black through frost bite he operated on himself. He used the micro-saw blade of a power tool and cut off the dead finger and thumb ends of his left hand. “I did it very slowly and carefully,” he said as if to reassure us.

This bit of DIY saved him, he reckoned, £6,000 in surgical fees. He should really be sponsored by Black & Decker.

The one nuisance he will admit to is that he tends to be late for gala dinners because without his finger tips he struggles to do up his bow tie. Baronet Sir Ranulph Twisleton- Wykeham-Fiennes, to give him his full due, comes from an old English family and is a cousin of the actor Ralph Fiennes. He never knew his father, a lieutenant-colonel in the Royal Scots Greys who was killed by a landmine in Italy in 1943, four months before the birth of his only son.

Ranulph (he is known by friends as Ran, no one has ever dared call him Also Ran) experienced 1950s public school life with its filthy rations, cold showers and lack of heating. Eton College was a great training ground for polar conditions. It was the same school attended by his great hero Lawrence Oates.

Captain Oates is remembered for his last words, “I may be some time,” uttered when, without hope of survival, he left Scott’s tent to die in a blizzard.

Fiennes, I am sure, would do the same if he had to. And boy has he come close.

Curiously the thing that most nearly killed him was not the poles or the deserts or avalanches. It was Dairy Milk. After one polar expedition he found he had an excess of 2,000 chocolate bars – family size – left over.

On the waste not want not principle he decided that he would eat one giant bar a day of his most beloved food stuff. Result: near death by chocolate. Surgeons had to jump start his heart 13 times before they could bring him round.

If you look at his career, it was obvious Ran was destined to become a solo maverick. As a young man he was chucked out of the SAS when he decided on some freelance demolition. Offended by the construction of an ugly concrete dam built for the film Doctor Dolittle, in the lovely Wiltshire village of Castle Combe, Fiennes laid dynamite charges with timed fuses. Unfortunately the dambuster was rumbled by local bobbies, heavily fined and thrown out of the SAS to which he had been perfectly suited.

His greatest gift is, perhaps, not in the field of endurance but as a first-class writer. His biography of Captain Scott is a superb and convincing defence of the much-maligned explorer. Fiennes despises the fashion for destroying national heroes and Scott, to his mind, was a great man and the victim of ignorant prejudice.

The book was intended to put Scott back on his pedestal. Failure, he argues, is in the nature of the business. What makes the book so riveting is that he has done exactly what Scott did – but without dying.

Of all Scott’s legion of biographers, only Fiennes has trudged over the crevasses of the Beardmore Glacier or walked 1,000 miles with poisoned feet. To write about Hell it helps to have been through it. He worships Scott as much as he does Amundsen (who beat Scott to the South Pole) and Shackleton.

Most of us will never fully know what horrors the Antarctic holds, thank goodness. But just reading about the South Pole is enough to make you shudder.

Fiennes brilliantly describes Shackleton’s anemomania (literally “wind madness”) and the intense, sapping cold of manhauling over the South Pole for 90 consecutive depot-less days, down to one mile an hour, every last ounce of protective fat gone from the body, sliced by razor winds in marrow-freezing temperatures.

Recounting the suffering of Scott’s team (whose cheerfulness remained even when death was certain) he reflected on his own in jungles, deserts and mountains: the broken teeth, kidney stones, torn off digits and rotting toes.

But the South Pole is something else. “The Antarctic teaches you real pain,” he writes.

He should know. On his farm in Shropshire he no doubt in his spare time watches Antiques Roadshow, his feet up with a nice cuppa.

But one rather hopes that when Ran pegs it he will be up Everest, on a sand dune or somewhere suitably desolate. His mission has always been to feel alive.

“Retirement holds no allure for me. Golf and fishing are for when you’re half-dead.”

Considering what he has been through in his amazing career, half-dead sounds infinitely preferable.