A Portishead man has spoken about the "terrifying" moment he had to be airlifted as he tried to reach the base camp of K2 in Pakistan.
Saadat Mumtaz, 48, was doing the climb for Brain Tumour Research, after his mum Saeeda died in 1988.
But during the trek, the experienced adventurer suffered from severe altitude sickness.
He reached as far as Urdakas, 4,034 metres up the mountain, before he had to be extracted by helicopter to receive treatment.
If left untreated, altitude sickness can lead to life-threatening high-altitude oedema accompanied by weakness, loss of coordination and hallucinations.
"Around the day before we reached our finishing point, I began to feel unwell," the 48-year-old said.
"I was exhausted, felt breathless and had sleepless nights where it felt like someone was choking me. I had heard of people dying in their tents during the night and I was terrified that would happen to me."
A helicopter took Saadat to hospital while his two sons – Sinan, 18, and Hashim, 20 – went on to complete the trek alone.
Doctors gave Saadat the all-clear after a CT scan and ECG, but it was another three days until Sinan and Hashim were able to be told their father was safe and well.
"Within half an hour of being in hospital my breathing returned to normal and I felt fit and ready to go back and join my boys," said Saadat.
"As a parent, you want to remain strong for your children and all I could think about were my two sons, they had no idea how I was, and I was worried about them."
Saadat returned to where his aborted mission began after being discharged in time to meet his sons as they returned from a successful trek.
Their reunion was "full of emotion", he said.
Saadat’s mother Saeeda Bano, from Sargodha in Pakistan, was diagnosed with an inoperable glioblastoma in 1983, after spells of passing out from debilitating headaches. Radiotherapy and chemotherapy treatment was deemed too risky and Saeeda died five years after she was diagnosed, aged 34.
Just 12% of brain tumour patients survive beyond five years of their diagnosis, compared with an average of 50% across all cancers. Despite this, only 1% of Britain’s national cancer research spending has been allocated to brain tumours.
Once fully recovered, Saadat plans to ride his motorbike 5,100 miles from Bristol to Pakistan, continuing a fundraising quest which has already seen him raise £1,370 for Brain Tumour Research.
"I underestimated the toughness of this challenge," he said.
"Although we did lots of training the erratic temperatures, high altitude and varying terrain took their toll on me physically. It took a tremendous amount of mental strength to get as far as I did."
Mel Tiley, community and development manager at Brain Tumour Research, said: “We’re incredibly grateful to Saadat and his sons for supporting the charity in this way. His determination towards this challenge in memory of his mother is heart-warming and we’re pleased he is on the road to recovery with his own health."
The charity is calling for a national annual spend of £35million in order to improve survival rates and patient outcomes in line with other cancers such as breast cancer and leukaemia and is also campaigning for greater repurposing of drugs.
See Saadat’s JustGiving page for more information on how to contribute to the family's campaign.