Two weeks ago Tasmanian climber John Zeckendorf was literally on top of the world having conquered Mount Everest.

Zeckendorf is back in Hobart having joined a small but elite band of Australians to have made it to the summit.

He is also the only Tasmanian to achieve the feat, according to the Himalayan Climbing Database.

The climb is a well-documented feat of danger and endurance, but for Zeckendorf, it had extra challenges having been hit by gastro along the way.

The sickness could have ended his attempt, but despite “running on empty” he persevered, even when dead climbers were being brought down the mountain past him.

“As we were coming up the mountain they were bringing bodies back down, people that had died recently … by trying to go to the summit in the wrong conditions,” he said.

This season 10 people died attempting the summit, including Australian Francesco Marchetti in May.

“It’s tremendously inconvenient when you’ve got a onesie on and a harness and you are on a 45-degree ice slope,” Zeckendorf told ABC Radio Hobart.

“I basically bleached out all the energy I had, and I didn’t have much anyway.

“So by the time I started summit day I was literally drained. I had nothing in the tank whatsoever and you can’t eat as much up there anyway, you basically snack.”

While climbers burn up about 1,500 calories an hour, he estimates at that stage of the climb they were eating only 100.

John Zeckendorf says the final 50 metres was more thrilling that the summit. (ABC News)

Climbing Everest is a staged approach through a series of four camps with a final assault, the timing of which depends on the weather.

Zeckendorf said he had made an agreement with his guide at the start of the climb to turn around if the guide thought it was risky at anytime to go on.

“I had a Sherpa with me who had been up the mountain 14 times, we had an incredible team … you put your trust in them,” he said.

Just in case, he took some medication to stop any traces of gastro on the final ascent.

Not all of Zeckendorf’s team made it to the top. They started out with seven climbers, three guides and 11 Sherpas. By the summit that number had halved because of various reasons including injury.

Despite the focus on the summit, he rates the ice flow between base camp and camp one as the most dangerous.

“It is as steep as climbing Mount Wellington but it’s ice,” he said.

“If you can imagine chunks of ice that are as big as … office blocks and that’s moving down a hill basically at 3 feet every day.

“So as you are going through that it is a very dynamic environment, it’s a very dangerous environment because you are never quite sure when the next ice block is going to fall.”

Most people start climbing with the tank full but I was starting the summit literally empty and the reserve gone

Zeckendorf’s climbing team had reduced by half by the time they approach the summit (Supplied: Joh Zeckendorf)

The section between camps three and four was another eight hours of “very hard climbing”.

Some of the challenges included the impact of the sun during some parts of the climb.

“It was about 35 degrees [Celsius] so when the sun is out it’s a bit like a Tassie sun you don’t need an awful lot of sun to feel like its really hot,” he said.

“The sun reflects back off the snow, so the sun is really bad.

“Camp four is the start of the ‘death zone’. You are at 8,000 metres and you have only got one more ‘Mount Wellington’ to go — so a 900 metre climb to go — but it’s the steepest and some of the trickier bits on the mountain.”

The conditions were so arduous in the high-altitude environment, at one point he took half an hour to make 20m.

On the way up to the summit on Everest. (Facebook: John Zeckendorf)

Reaching summit not the pinnacle

There was a white-out when the group finally reached the summit.

But for Zeckendorf, it was reaching what is known as Hillary Step just before the top, which was the most exciting moment, when he realised he was going to make it.

“After Hillary Step and we’d done more and I was ready to turnaround a bunch of times … my Sherpa kept feeding me food, pulling my mask down,” he said.

“He literally parented me up this mountain … I had killed off the reserve, I literally had nothing left.”

The sight of his co-climbers ahead on the summit was when he “teared up”.

It was wasn’t until that moment I realised I was actually going to make this. I started tearing up and the whole journey came down to that moment.

“It took me 10 minutes, but then I was enjoying that 10 minutes because I knew at the that moment nothing was going to stop me now.”

‘Amongst the stars’

Zeckendorf is used to spectacular night skies in Tasmania, but the stellar view from Everest was something else.

“When you climb in Tasmania you can see the stars are above you and you can see that there is a gap and you’re down on Earth,” he said.

When you are near the top of Everest you are so high up you can see the curvature of the Earth and as you are looking out at the stars they are not above you are almost amongst them.

Everyone who has successfully climbed Everest is asked why they did it.

Mountaineer George Mallory famously answered “because it’s there”.

For Zeckendorf, it was the physicality of the challenges but he also found it very spiritual experience.

“It touches you in a way you are not touched wandering around in normal life, that’s probably closer to my answer.”

Oxygen is need for the last of the climb (Supplied: John Zeckendorf)