The explorer Sir Ranulph Fiennes, 59, was educated at Eton before entering the armed forces. Described as "the world's greatest living explorer" by Guinness World Records, he has led more than 30 expeditions, becoming the first person to reach both poles by surface travel, and the first to cross the Antarctic unsupported. In 2000, he abandoned his final attempt to reach the North Pole unsupported after suffering severe frostbite. In June this year, he had a heart attack and underwent a double bypass operation. He lives in Somerset with his wife Ginny.
If you had died while on any of your expeditions, would it have been worth it?
Monica Pullen, Gosport
I do expeditions as a way of making a living. I have done for 32 years - that's how I pay the bills. So you could ask the same question of a carpenter, a repairer of telephone lines or a salesman. Statistically, a salesman driving down the motorway is far more likely to end up dead or severely injured in a crash than any polar traveller.
If you had been in Captain Oates's shoes, would you have gone out for a walk?
Jon Lambourne, London
Yes, definitely. But I would have gone three days earlier so that I could have cut out three days and nights of extreme pain and given the others a better chance. If Captain Oates had decided to go for his walk a little bit earlier, there's more than a good chance that they might have gone the extra 11 miles to the depot.
Do you ever go on package holidays?
Bob Yarker, Manchester
Yes, we do. My wife and I, with our friends, like to hire a chalet for skiing. But I don't like lying on beaches; I think it's quite dangerous, considering the risk from skin cancer.
Why did you amputate your own fingers after your aborted mission to the North Pole in 2000? And how many fingers and toes do you still have?
James Richards, by e-mail
I've got all my fingers and toes, but they aren't the same shape or as long as they used to be. In fact, my right hand, apart from one twisted finger, is as it should be. On my left, my fingers are all stubs - all a result of the North Pole expedition in 2000.
When I got back from that expedition, I was advised to wait for at least five months to have my fingers amputated. But I didn't want to hang around with these dead talons, looking like a sort of witch. And the Gestapo were absolutely right in going for people's fingers - every time I touched something, I almost hit the ceiling. I'm a semi-carpenter, so I picked up a micro-saw and a vice in the village shop. I sawed each finger through from one side, and then turned it round and sawed through the other side - like a log. My physiotherapist said I'd done a really good job, but my surgeon wasn't quite so impressed.
Do you take music or books along with you on your expeditions? If not, how do you entertain yourself in the evenings?
Dean Croft, Barking
We don't have time for entertainment. If you are hauling your guts out for 10 hours a day in zero temperatures, you get very knackered by the time you put the tent up.
But there was one severe blizzard during our crossing of the Antarctic continent, and we had a few hours waiting for the worst storm to subside. My fellow explorer, Mike Stroud, drew a chessboard on the lid of the cooking pot. Because he was doing detailed scientific tasks during the expedition, he had pee bottles. Mine were red and his blue. Some of them full, some not. We played chess with pee-bottles, basically. He taught me how to play and then consistently won.
At a time when the slopes of Everest are crowded with climbers, are there any great challenges left?
Claire Hopgood, Southampton
Everest's slopes are indeed crowded, as are the routes to the North Pole and the South Pole. The seas are full of people rowing across them, and the air is thick with hot-air balloons floating over every mountain and every ocean. But, according to National Geographic magazine last year, only 5 per cent of the world's oceans have been explored. And, of course, there is space - if you're one of the lucky few who have the training and the technology.
Have you ever thought: 'I'm really cold and I want to go home?'
Julia Wyatt, Aberdeen
Yes. I have frequently thought, while on an expedition, that I'm unbelievably cold and desperately wish to go somewhere warm - home would be great, but anywhere warm would do. But as that wasn't possible until I reached my goal, or ran out of food, I used the impulse to concentrate my mind on trying harder and going quicker.
Are your exploring days over?
Ian Farrington, by e-mail
I don't know. I certainly hope they're not. If you had asked me that question 10 years ago, I'd have said the same thing. I've been very busy writing a book about Captain Scott, but I rang up Mike Stroud earlier this year and asked if he would like to have a quick holiday. I had wanted to do what everybody else does and climb Everest. But then we discovered that it would take three months. So Mike suggested that we do something that he'd wanted to do for six years, which was to attempt seven marathons in seven days on seven continents. It appeared to be impossible, but we're going to have a go at it next month.
Many explorers claim to have come closer to God - or some other spiritual presence - at the top of a mountain or out in the wilderness. Have you ever had a similar spiritual experience while exploring?
Lily Scobie, by e-mail
No, I haven't, but I can quite understand why it happens. Although I'm standard Church of England and would like to pray, I am very lazy, so I normally don't. But when I am extremely worried by what lies ahead of me on an expedition, that helps me to pray. It's a very selfish motivation, but that's the fact.
What drives you into the planet's bleakest regions? Is it curiosity? Inquisitiveness? Madness?
Bev Morgan, Cardiff
It's not romantic. It's commercial. It's not because it's there; it's because expeditions need 100 per cent sponsorship and they do not get 100 per cent sponsorship unless the corporation gets publicity. And the media are not interested in an expedition to Primrose Hill, however bleak the weather is that day.
After your recent heart bypass operation, I should think you had to convalesce for a few weeks. Were you a good patient?
Gillian Morrison, by e-mail
I was told that, for eight weeks, I should not drive nor take any hard exercise. But four months after the bypass, I'm hoping to run seven consecutive marathons. I had to start by trying to walk uphill. I would get out of breath within a few steps and have to sit down. My walking was more like lurching. But within two weeks I was jogging for an hour, and within a month I was jogging for two hours. At the end of three months I was doing three-hour runs, and two weeks ago, I did my first post-op marathon. I had a monitor that told me if my heart rate got above 130 beats a minute, which the doctors say it shouldn't. The bypass has slowed me down enormously. I was very fit before I had it, and now I'm trying to regain some sort of reasonable fitness.
'Captain Scott' by Ranulph Fiennes is published by Hodder & Stoughton (£20)Reuse content