South African Paul Trümpelmann, 33, a specialist registrar anaesthetist at Southampton General Hospital in the UK, summited Mount Everest on May 24. First delayed by the Olympic torch expedition, he and his companions braved ice falls, blistering winds and oxygen deprivation to make it to the top of the 8,850m-high mountain. He describes what it's like to reach the world's highest point, and come down again past the bodies of other climbers, still frozen in the ice

I'm not an experienced mountaineer, and before 2004 climbing Mount Everest hadn't even crossed my mind. Then, around three weeks before I was due to leave I started to have doubts. I met a guy from New Zealand who had summited Everest. He had climbed the north side, the Tibetan side, and he talked for two hours about how tough it was and how many dead people he saw. It was really depressing. Then I spoke to a friend who said: "Paul, if you don't go you're going to regret it for the rest of your life." From then on I was fine.

I didn't do any specific training. I did a lot of mountain biking, running and endurance work in the Perbeck Isles, walking for 10 hours a day with a 30kg backpack. But with Everest, it's 95% mental. Most of the preparation you do for summit day happens on Everest. It happens from the day you arrive in Kathmandu.

By the time we flew to Kathmandu I was being meticulous about my food and hygiene. You can pick out the guys who are going on an expedition: they push people away. They create a protective environment around themselves and are totally paranoid about getting sick. If somebody coughs in the room, they all sit up and stare.

We started in Lukla and trekked through a dense and beautiful forest with remote settlements of people. We met a Buddhist lama who blesses all the climbers on the way up. He took my head in his hands and bumped it against his own, twice. Then he recited a prayer, looked me in the eye and touched my shoulders and my knees. I'm not religious but I was glowing inside. It was as if I suddenly had loads of energy, like someone had stuck a battery in me.

It took my companion, Tanner, and me eight days to trek to base camp, where we spent three days acclimatising. You have to give your body time to adapt to the altitude. From the base camp we did our first trip up the mountain to camp one, at 6,065m high.

Normally, from there, we would have progressed to camp two, which is 6,500m high and part of the acclimatisation process. But this year was different because the Chinese had closed the mountain from May 1–10 to make way for the Olympic torch. It was really frustrating not being able to ascend. We spent five days in a lodge in the valley, resting and eating to fatten up.

Once the Chinese had summited, it was game on, but we had to wait a further five days at base camp for the weather conditions to be perfect. The mountain is closed on the Tibetan side so the Nepal side was busier than usual. I don't think the Chinese realised how dangerous they made the mountain this year. People had no time to acclimatise properly – some even climbed without oxygen.

After each climb we had to rehydrate. We would boil two litres of water to get us through the night. We also had to try and eat as much as we could, but we were too nauseous to have an appetite. Tanner and I had energy gels – we got hyped up on them and started counting down the minutes until 8.30pm – set-off time.

Summit night was eerie. It was hot up there and dead calm, which was worrying because you generally want a bit of wind. We set off in the darkness and all I could see were little yellow spots on the ice – the head torches of other mountaineers. Within the first two hours I was sweating like anything. I wanted to take everything off, but I knew that if you start warm you stay warm – it's when you start cold that you're in trouble.

At around midnight we reached the balcony, a small platform at 8,400m, and it was like someone had flicked a switch. Bang, a wind came up out of nowhere. By this stage I'd sweated so much my gloves had frozen and were like rocks. The wind gave a lot of people frostbite. They were caught with their hats off and it burned their faces and ears. I didn't have my goggles on and I burned my cornea. My eye was blurry for three days.

It wasn't until I saw the south summit that I realised I was actually making it. It was still dark but the horizon was going pink, and I could see the curvature of the earth. I realised I was really high – it was like being on a plane. I could see so far around me – the moon above, the clouds below and all these little flashes going off everywhere. It turned out the flashing was lightning from storms so far away we couldn't hear them.

When we reached the summit ridge the sun came out and we rested. The mask I was using had frozen up and I was struggling to breathe. The inlet valve was broken but I didn't have the presence of mind to clean it. I told one of my companions that I was struggling and he helped me, but it was strange. I can see how hypoxia changes your reasoning. Something that is obvious at ground level isn't so obvious up there.

Once it was done, suddenly I could breathe and everything became clearer. I can see how people make mistakes and die up there. We normally breathe 21% oxygen, but at that height it's only 7%, so you get this tingly, warm feeling. I think if I had to die, that's the way I'd like to go. Just take the oxygen away slowly. It's peaceful, like falling asleep.

Below the summit is the Hillary step, which was dry and precarious. But I knew I had to go with it, trust it. I was clipped onto a rope as thick as a shoelace and had to lean back, and as I leaned, suddenly my crampons gripped. From the Hillary step I could see right down the western cym to Camp Two, 2km below. Then I looked over the Tibetan side and that was a straight drop too. If I had caught one of my crampons I would have been in trouble. That shoelace wasn't going to keep me up, that rope was in my mind. And I was hypoxic, which could have made for a disastrous situation.

The summit was another 20-minute climb from the Hillary step. I walked up an ice peak littered with rocks and along the edge of an overhang. Those things can just break away. You realise you are literally walking on thin ice. Then suddenly, out of nowhere, the summit appeared. It's a little peak covered with prayer flags. And I was there, on top of the world.

I had a scare going back down. About halfway down the balcony I slipped. If it wasn't for the anchor I'd have slipped to my death. I sat up and looked left, and there was a dead body next to me, frozen in position. That was a wake-up call. I thought: "I've got to get down, I've got to be safe."

I made it back to camp at about 10.45am, having climbed through the night and through the previous day. They call this section the "death zone" because you've got to look after yourself. You can't look after anyone else – you don't have it in you. You hear stories about people who are incapacitated and others just walking by. This isn't being selfish, you simply can't help them. I'm a doctor and I'd help anyone, but in this instance you just can't.

I sat alone in front of the tent, dozing. Then I got this jerk and thought: "I've got to wake up." I'd heard a story about a guy called Pommie who fell asleep with his feet outside his tent and his boots froze to his feet. I got into my tent, sorted my things out and slept.

Tanner came in about three hours later. He was really out of it. He hadn't been wearing his oxygen mask and was dehydrated. Luckily I woke up. His face was swollen and his ear frostbitten. I forced him to drink and put his oxygen mask on. I kept saying to him, "Look, man, you've just summited Everest, there's no point in dying now, you've got to have oxygen." He gradually got better and we both fell asleep.

Climbing is a hugely satisfying sport – the adrenaline, the buzz, the kick of summiting. The 10 minutes I spent on the summit were amazing. But I do realise how selfish it is. It's egotistical and self-satisfying, and you turn your back on the people who love you. I could hear the difference in my mother's and sisters' voices once I got back to Base Camp – they sounded so relieved. I'm sure I'll climb more mountains, but not right now.

• Paul Trümpelmann was interviewed by Katie Monk.