A dad-of-two was rushed to hospital after swimming non-stop from Devon to Swansea, after becoming the first person to swim the length of the crossing using breaststroke alone.
Phil Warren, 52, braved the freezing temperatures of the Bristol Channel, becoming one of four people to ever swim the distance, and even faced being stung in the face by a jellyfish.
The electrician set off from Ilfracombe last month, and swam up to Gower the following evening in his Speedos and a swimming cap, report Wales Online.
However, after completing the gruelling 31 miles in just under 22 hours, the charity swimmer had to be rushed to hospital with hypothermia.
Speaking about his achievement, the dad said: "It was hard but amazing - a pod of dolphins swam next to me at one point, checking me out.
"But after being in the sea that long, the strong tides having added an extra few miles to my journey, it did get very cold. Luckily my partner Nic is a paramedic and an A&E nurse, so when I finally arrived on the beach at Gower she took one look at me and went, 'Yeah, he's not right'."
On being assessed by paramedics, he continued to say: "I was blue, completely exhausted and had a core temperature of 31°C. I was then rushed by ambulance to Morriston Hospital where they also found fluid on my lungs. They did blood tests, chest X-rays and set about warming me up slowly. I was in for about eight hours before getting the all-clear."
Phil added that the rules of the challenge meant he wasn't allowed to hold onto the side of his support vessel at any stage and all his food was served up in liquid form - thrown to him on a rope whilst he was in the water.
"All part of the adventure though, I suppose," added Phil, saying that there's a very good reason behind him pushing himself to the limit.
The 52-year-old said: "I'm raising money for Mind, the mental health charity.
"It's a cause that's very close to my heart because, about 10 years ago, I suffered a total breakdown. All the things I'd been bottling up my whole life just crept up behind me and hit me like a ton of bricks, all at once.
"A huge black cloud descended and I remember thinking, 'I've got to get out of here'. I ended up leaving the house and walking and walking for 12 hours straight, crying the whole way."
Thankfully, Phil got the help he needed and now tries to make sure no one else in a similar situation goes without.
So far he's raised thousands for his chosen cause, having previously completing open water swims between Penarth and towns in Somerset, like Weston and Clevedon.
Speaking about his motivating factor, he said: "When I grew up mental health problems existed but no one talked about them - the attitude was very much 'pull your socks up and get on with it'.
"We've come a long way since then, but there's always more that can be done to reach out to those who might feel like they've nowhere to turn."
To donate to or find out more about Phil's fundraising efforts, click here.