You'd expect an Everest climber to feel on top of the worl on his return, but Kildare man Ian Taylor is haunted by his experience.

Oh, shit." Ian Taylor could not believe it was happening. The figure, teetering on the knife-edge ridge, stumbled backwards, clasping at his frozen oxygen mask, inching closer towards certain death.

On one side, the snow-drenched ravine tumbled 8,000ft, on the other was a sheer drop of 10,000ft.

"I shouted at him to stop," says Taylor, recalling the moment Mount Everest revealed its darkness. "He shouted back, 'It's Martin. I'm blind'."

It was bitterly cold, minus 35° Celsius. Taylor was almost in touching distance of the summit and his childhood dream of conquering the world's highest peak. He had journeyed through the darkness of night, climbing the rugged, unforgiving terrain littered with the frozen corpses of climbers who had failed to tame Everest.

"We were told to watch out for a body on the way up and warned we would have to step over it," recalls Taylor. "I was having this vision of tripping over it, landing right beside it and having it stare me right in the face."

To climbers intent on reaching the summit, a dead body is simply just another gruesome obstacle in their way. But when Martin McGarvey, a climber Taylor had met on the trip, lost his sight on one of the most treacherous parts of the climb, the fear of death became all too real.

"I suddenly knew I was at 28,700ft," says Taylor recalling how, at that very moment, the darkness lifted and the stark reality of daylight flooded around him. "It was bitterly cold. When you are climbing at that altitude there is a very close sense of death. More than 200 people have died on this mountain."

On Everest, the area above about 26,000ft is simply referred to as the "death zone". This is where oxygen levels are at a fraction of what they are at sea level, winds constantly whip up into gales and temperatures can plunge to 100 degrees below zero. The combination of fatigue and low oxygen can leave you lost in hallucinations, can cause snow blindness and ultimately, death.

"I though we were both going to die," says Taylor, still struggling to come to terms with the experience. "I had seen a body off to the left and I had visions of disaster. I shouted at him to get off the ridge and to start walking back along a ledge which was only about 12" wide."

He made his way towards his blinded colleague and eventually brought him to safety with the help of their Sherpas, the local guides employed to help climbers navigate Everest. He may have managed to stop him from falling over the ridge, but Martin was still blind and they were still in the sub-zero temperatures of the death zone.

"I remember looking at the Sherpas and seeing the shock on their faces," says Taylor with a chill. "They are the ones you look to for support and encouragement, and to see these people scared. . . I just kept on thinking, 'I'm not going to get out of here'."

It was then he almost broke down. "I didn't know what was going to happen next. I said to the guy we have to help him, stay with him. But my Sherpa shouted at me, 'We must go to the top. We have to go to the top.'

"He gets a $1,000 bonus if he brings a climber to the summit. The average wage in Nepal is $260 a year, so $1,000 is probably the equivalent of €100,000 to them. That's where the whole selfish thing is. You quickly realise morals are thrown out the window up there."

As Taylor struggled to the top, every movement was a monumental effort. The lack of oxygen had made him sluggish and it took all his concentration to focus on taking his next step while his mind screamed at him, "I can't go on. I can't go on. I need to get out of here."

"I really felt I was on the verge of death. I knew the terrain we had left to cover and thought if Martin had gone blind, so would I. I knew that if that happened, I would not make it. The level of concentration for every step I took was unbelievable. You haven't slept for 36 hours, it's freezing cold, your digestive system has shut down and you can't eat, and physically and emotionally you're drained."

As the summit came into focus he saw more dead bodies. "You are in a heightened state of awareness. All I knew was that I didn't want to turn into them," he says.

And then. . . he was there, on top of the earth. At 12:02am Irish time, on Friday May 23, Ian Taylor became the youngest Irish man, and first Kildare man, to stand on the top of the world.

"I was just happy thinking there were no more steps to go," he says, with little joy. "I thought, 'I'm here and I did it.' I proved to myself I could do it. I did enjoy it for a few minutes. But then the cold hits you and you remember where you are. When I was on the top I remember thinking 80pc of the accidents happen on the way down."

After three years of planning, Taylor had completed the journey he undertook with his friend Graham Kinch. The goal was to climb four mountains in four continents raising €1 for every foot climbed, a total of €85,000. This money will help build a much-needed primary school in the Ugandan village of Kitandwe, to be built in partnership with charity Fields of Life. They began by climbing Mt Blanc last June, followed by Kilimanjaro in September, Aconcagua in January and now Mount Everest. The climbs cost them €72,000 each, over the three years, and €32,000 just for Everest alone.

Taylor has joined an elite club. Only 20 Irish people have summitted Everest, and fewer than 2,000 people in the world have reached the top via the South East Ridge. But the experience has left a dark imprint on his psyche.

"Everyone wants to climb Everest for the sheer joy of being on top of it, on top of the world. I didn't have that sense of joy," he says. "On other mountains I got a great thrill at being on top. But I think, maybe, Everest is only ever enjoyed in retrospect. It was an uncomfortable environment."

He was not joined on the summit by Kinch, who had to turn back on the final approach to the summit due to injury.

"He had cracked a rib from coughing. The 'Khumbu cough' wipes out more climbers than anything else," says Taylor. "I think he knew on that particular climb it wasn't to be. He's disappointed he didn't get there. But the point in climbing four mountains in four different continents was to get someone to the top of each and we achieved that."

A little over two months since climbing Everest, Taylor is still trying to remember, understand and contextualise the feat.

"No one can really understand what it's like," he says. "When you go above 26,000 ft it doesn't matter how prepared you are, because nothing can prepare you for it. All you can try to do is limit the potential danger. The danger lies in what the atmosphere does to your body. Your body is literally dying at that altitude.

"I am still trying to remember exactly what happened to me on the last day. You are so focused on the next step you immediately forget about the last one because it's not important any more.

"Your blood is like syrup in your veins. You are not thinking straight, even if you think you are. It's like having five or six pints in you and then trying to perform for 10 to 15 hours."

The memory that haunts Taylor most is experiencing the inhumane coldness of "summit fever", where people get locked into a trance-like state trying to reach the summit.

"I really believed that I was truly on my own on Everest," he says almost in a whisper. "People are so driven they walk past people in trouble to get to the top. The attitude is: if you can't help yourself up there, tough."

Now, Taylor is focused on finishing the fundraising efforts, but the shadow of Everest still weighs heavy on him.

"Two people died when we were there," he says solemnly. "We saw them 10 hours before they died. Everest certainly conquered those people. Everest will show you your limits and show you who you are. It also shows you your values and what type of person you are. You see yourself in a different light. Coming out of there alive it shows you a whole new side. It probably shows me I'm reckless and very selfish and I don't have a sense of community.

"That is maybe what we learnt from the people in the African school. I was very selfish. I just put my life in that scenario and I could have easily died. I saw things there I didn't like. I learnt positive and negative things about myself. You have to assess who you are and maybe that's what it's about. Maybe some people just have to climb Everest to find out."

For more information on helping Ian and Graham raise €85,000 to build a school house in the Ugandan village of Kitandwe in partnership with the charity Fields of Life, visit www.everest2008.ie

- John Costello