A university student studying nutrition and health caught hypothermia after climbing Snowdon – the highest mountain in Wales – in a pair of Superman pants.
Nathan French, 19, from Liverpool, was raising money for the Dementia UK charity in honour of his grandmother, who has the condition.
Emergency services were called to treat the 19-year-old who became unwell while taking the train back down from the 1,085-metre summit.
Paramedics found his blood sugar and blood pressure had dropped and he was beginning to suffer from hypothermia.
However he insisted he had no regrets about taking up the challenge for the charity close to his heart.
Nathan French, 19, from Liverpool, caught hypothermia after climbing Snowdon last Saturday
The 19-year-old student was raising money for Dementia UK, a charity close to his heart
He said: ‘For a while I have wanted to do something to raise money for Dementia UK. My nan has dementia so it is something that is close to my heart.
‘However the people that know me will know I always like to do something with a bit of a twist and something a bit fun so that’s how I decided to do the climb in Superman underwear.’
He added: ‘This is the first time I have ever climbed a mountain like this.
‘I keep fit and I am always in the gym but this was different.
‘It was very cold and it got progressively colder the higher up we got.
‘The hardest part and when I really started to struggle was when I reached the top, but my dad who did it with me was behind me and I had to stop and wait for him.
‘That was a very long and cold five minutes waiting for him.’
But he said it was when he was on the train back down from the summit that he started to feel sick.
‘I started to go deaf and my sight started to go funny. It was at this point my dad decided to ring for help’, he recalled.
He said: ‘The hardest part and when I really started to struggle was when I reached the top’
Nathan, who is a student reading sport, nutrition and health said: ‘This is the first time I have ever climbed a mountain like this’
He said the paramedic described his actions as ‘very silly’ but understood why he had done it when he explained it was for charity.
‘It was very emotional completing it and I cried at the top because it does mean a lot to raise this money’, he said.
‘It is hard to raise awareness of dementia but I am just going to do what I can to raise money to try and help those with this terrible illness.’
He has so far raised a total of £2,268.06 after last Saturday’s climb.
He said he had received some abusive comments on social media following the incident.
But he defended his actions, saying: ‘There are lads my age robbing and into drugs and violence, and I’m out there doing something big for something that matters and I get the hate.’
Mr French became unwell at the peak of the mountain and had to call emergency services
Miles Hill of Llanberis mountain rescue team said the outcome could have been much worse.
He said: ‘While we are sympathetic to his charity fundraising for a very worthy cause, we would question the planning and perseverance which went into his day on the hill.
‘Anybody walking in the mountains should always carry enough equipment, clothing and food to be self-sufficient for the duration of their trip, including adverse changes in weather.
‘Even with temperatures in the teens, with minimal clothing Mr French would have been highly susceptible to wind chill.
‘If the train hadn’t been running from the summit, the outcome could have been very different. While charity events in your kecks are commendable, it’s not a trend we want to see started.’
He added: ‘We hope Mr French is back in the mountains soon, perhaps in the full suit (cape optional), rather than just the underwear.’
Mr French said has received a number of negative comments on social media since his misadventure on September 9