The Rotarian and paraglider from Berry was inching towards Camp Three which is at 7300 metres, until he succumbed to a chest infection on Sunday.

"You're not going to recover at that altitude, so I've had to come back to base camp, which is at 5300 metres," Ken told the Register.

Ken was gearing up to fly off the summit on Tuesday to raise money for eradicating polio. Despite the hurdle, he remains determined he can make a swift recovery and "get back to business".

"It's a huge undertaking and its basically your whole life for a couple of months, constantly looking after your own health," he said.

"And unfortunately mine's failed at the moment.

"But you have to be optimistic, there can be so many things that go against you. You've just got to hold out hope. The dream is still alive."

Ken has climbed many mountain peaks, including the world's sixth highest mountain Mt Cho Oyu in Tibet, where he successfully paraglided back to base camp in 2014.

But this journey marks his first Everest attempt.

And while his chest infection has put a bump in the road, it's not the only thing that brings uncertainty to the expedition. His crew will now keep a sharp eye on the conditions for any impending blizzards or steep temperature drops.

"If that weather window and my health isn't there, we'll probably pack up and go home which will be a huge disappointment," he said.

"But I do think the objective of raising money and awareness for polio eradication has been obtained."

If all goes to plan, Ken will become the oldest person to achieve the impressive feat of paragliding off Mount Everest, as well as the oldest person to reach its summit.

He will also be the first to do it legally, after three years of negotiations with the Nepalese Government.

"We've managed to obtain the first ever permit to fly a paraglider from Mount Everest," Ken said.

Ken is being treated by a doctor and will get the all clear within a few days.

Gathering himself for the final push, he is grateful to be surrounded by a supportive team including two Sherpas and his son, Matt, who was waiting for him at base camp on Sunday.

"He said he wanted to be there for me ... which is very humbling," Ken said. "One of the positives of coming back down is that he's here."

To donate, visit: https://www.flyfromeverest.org/

We depend on subscription revenue to support our journalism. If you are able, please subscribe here. If you are already a subscriber, thank you for your support.