Ranulph: Spiders used to be quite a big problem for me
He's almost broken his body taking on extreme endurance tests. So what does frighten Sir Ranulph Fiennes? Ella Walker finds out
'Some hot expeditions have been excruciating, and some cold ones have been pretty lethal," muses Sir Ranulph Fiennes mildly.
The Berkshire-born adventurer - full name, Sir Ranulph Twisleton-Wykeham-Fiennes, 3rd Baronet of Banbury - has, as the 'greatest living explorer', conquered both, so he knows what he's talking about.
Measured and polite ("Sorry, I've got a frog in my throat but I'll try and croak"), with a gravitas that winds itself down the phone line, Fiennes is currently celebrating Heat, the follow up to his 2013 book, Cold.
It details his exploits in the most scorched and sweaty environments on Earth, from discovering the lost city of Ubar in Arabia after a 26-year search ("That was the best moment I can remember on any hot expedition"), to putting his body through the toughest endurance test known to man in April.
The 71-year-old teamed up with extreme marathon runner Rory Coleman to tackle the brutal, grinding Marathon des Sables - which amounts to running five and a half marathons across six days in the Saharan desert.
"Thanks to him and his knowledge I managed to get round, which I wouldn't otherwise have done," says Fiennes humbly. "As it was, we were very nearly caught by the camels."
To get insurance for the trip, Fiennes had to return to the surgeon who performed his double heart bypass, and was told, point blank, that he must not exceed 130 beats per minute.
"Normally I wouldn't in a typical day, I wouldn't go anywhere near it," says Fiennes earnestly. "But unfortunately, on three days we had 53 degree heat..."
Combine that with running on constantly shifting sand dunes and blazing plateaus that were "just like you can't believe - an oven", his doctor's demand that he take it slow simply wasn't viable.
He was also up against the organisers, who, for health and safety reasons remove people from the race who can't keep to a certain pace - even if they want to carry on.
"In other words, geriatrics get removed by the helicopter, which is called 'The Vulture'," Fiennes says with bite. "I knew Marie Curie would make over £2 million if I completed, and they'd make virtually nothing if I didn't - all this had a bad effect on my determination not to go more than 130 beats a minute."
Then came those camels.
"They have two evil-looking camels and they just plod forever," he says, "and if they catch you up, you're done. At one point, even though I had Rory with me, we were only 13 minutes ahead of these camels and therefore I must have gone a long way over 130 beats a minute."
Crossing the finish line, finally, he says was a "relief", but no, he wouldn't do it again. "Not even for Marie Curie," he adds. There isn't much he wouldn't do to raise money for the charity, after his first wife died of stomach cancer.
His current wife Louise, who he married in 2005, was glad he survived the epic adventure too, having emailed to say his daughter Elizabeth, 9, "wants her daddy back, not a corpse".
Since Elizabeth was born, Fiennes says it has had an impact on which challenges he chooses, but not enough to make him turn them down.
"I sometimes feel a sort of guilt that I never used to feel, but then I realise that no polar expedition people die compared to miners or people who drive on motorways a lot."
Fear of death might not come into the equation, but that isn't to say Fiennes has never felt fear. In fact, this rugged gent - who's scaled Everest, led numerous expeditions and experienced military combat - used to be scared of spiders. "I've never had a problem with scorpions or snakes," he says. "[But] spiders were a huge problem."
After being bitten by one as a child in South Africa, it wasn't until he was seconded as an officer in the British army, to the army of the Sultan of Oman, that he got a grip on it.
"Being frightened by spiders, by Arab standards, is totally wimpish," he recalls, remembering how, when he first met the soldiers he'd be living and working with, he knew he had to gain their respect. "We were wearing shorts because it was very, very hot, and a camel spider - seven inches across, hairy legs, - started crawling over my thigh, and I would, quite honestly, have screamed, hit it incredibly hard and run a mile - but, I was being watched and the fear of the disrespect of these guys was just a bit greater than the fear of the spider, so my lips clammed up and over the next three years, I gradually got used to them. By the time I left, I couldn't give a damn."
When he braved Mount Everest in 2009, it was an anxiety over heights and the loss of his first wife Jenny, after 38 years together, that drove him to the summit.
"I was just... I couldn't do anything, I was in a black mood, and eventually I thought, my life's going by and I'm not doing anything at all. Something must jolt me out of this non-existence, and I thought, well, what will definitely jolt me would be trying to do anything vertically.
"Normally I'd send my wife up the ladder to the gutters and hold the bottom of the ladder of myself - I really didn't like heights. Obviously, the highest mountain is Everest, so I thought I'd try that one."
Fiennes explains that it's taken a lot of hard graft to stop him becoming a liability on expeditions.
"The fact that I take a long time working out the sun's altitude using nautical almanac sight-reduction tables and sextant altitudes and I never passed Maths O Level, means I'm slow but reliable," he says wryly.
Fiennes cannot yet discuss his next challenge, hot or cold, "because we would want to be the first humans and there are other people, particularly Norwegians, who, if they knew that we were after this particular record, would accelerate their own efforts", but you can be sure it will be just as punishing and impressive as ever.
He's not a man to start taking it easy; his heart wouldn't be in it.
- Heat: Extreme Adventures At The Hottest Temperatures On earth is published in hardback by Simon & Schuster, priced £20. Available now