This image was posted on Nims Purja's social media along with the news that the rescue mission had been a success Photo / Instagram /Nimsdai
Atop one of the world's most dangerous mountains, former special forces soldier Nirmal Purja MBE was just days in to his world-record attempt to climb all 14 peaks of the Himalayas in seven months when he learned that a fellow climber was missing.
Purja, or 'Nims' as he is known, was descending Mount Annapurna in Nepal on Tuesday when the ex-Special Boat Service soldier was alerted that Dr Chin Wui Kin, 48, had been separated from an accompanying group.
The mountain is the 10th tallest in the world and is considered the globe's most dangerous 8000-plus metre peak. It was the first of 14 to be tackled by Purja and his team as part of Project Possible, an attempt to break the current world record by more than seven years.
Chin, an anesthesiologist and accomplished climber, had been left stranded for 36 hours on his own without an oxygen bottle, food and water after he became separated from a 13-member expedition during his descent from the 26,545 foot summit to base camp four - the first stop on the way down.
It was at camp four, at nearly 25,000 feet, that Purja and his team discovered that Chin was missing. However, rather than set back out up the mountain to find the Malaysian national, Purja was first forced to descend to base camp to retrieve oxygen for the rescue mission as a helicopter was unable to send any up.
He wrote on social media: "We were waiting for oxygen to get dropped off to us by helicopter so we could go and start searching for him on the mountains.
"I couldn't hold my team any longer at the extreme altitude risking their life. I was the last man to leave camp 4 and I had thought he [Dr Chin] was possibly dead by then on those dangerous slopes.
"Bear in mind Annapurna 1 is ... one of the most dangerous and technical hardest 8000m peak to climb."
On Thursday morning, Purja and three of his "strongest" climbers flew back up to 21,325 feet, the highest point possible, and roped down in to camp three from a helicopter which was paid for by Chin's wife.
The rescue team led by Purja, who served in the UK military for 16 years, included Mingma Sherpa, Gesman Tamang and Gyalzen Sherpa.
He said: "When the altitude is too great then we have to do a 'long line' rescue. We are literally underneath the helicopter and are dropped close to the site. We still had a long climb past camp four, the last base before the summit, and we realised that we had to work quickly."
Days before, Purja and his team had taken 18 hours to climb from camp three to the summit, but the four men reached Chin in just four hours in a feat that the former special forces soldier called "incredible".
Purja, who was awarded an MBE by the Queen in 2016 for his outstanding achievement on high altitude mountaineering, managed to move the injured doctor down from the summit to camp three by Friday, where a helicopter was able to drop a long line down to attach to Chin. He was then taken to Kathmandu Hospital.
Purja said: "He is alive but still in critical condition. I did go and visit him in hospital. He is with his wife and the medical experts and I wish him a good recovery."
According to the organisers of the expeditions, Seven Summit Treks, Chin had been without an oxygen bottle, food and water for more than 40 hours and it was his medical knowledge and familiarity with the mountains that kept him safe.
Mingma Sherpa, head of the organisation, told MailOnline: "It's a big thing to stay alive in that altitude without food, water, and oxygen". He described Chin as fine but not in condition to walk.
Project Possible began last week with the team successfully making the 8,091m ascent of Mount Annapurna.
Annapurna is avalanche-prone, technically difficult and has a higher death rate than Everest, the world's highest peak.