A cancer sufferer with a condition that makes him unable to sweat has pledged to risk overheating his body by taking on Sunday's London marathon in a bid to inspire hope.

Rich Martin, from Nelson Road, Merton Park, developed the condition – known as graft versus host disease – after having a lifesaving bone marrow transplant after having leukaemia diagnosed in 2009.

The 36-year-old, whose brother Chris has raised more than £18,000 for blood cancer charity Anthony Nolan by running the last two marathons, said he was determined to do it himself this year despite the severe risk it presents.

He said: “Obviously this is going to be a huge challenge because, if it is a hot sunny day, even walking that kind of distance will be very difficult because my body overheats so easily.

“Even if the weather is perfect I will be right on the edge of what I can physically take.

"I’ve estimated it’s going to take about 10 hours to complete.

“Last summer I spent several days in my bathtub filled with cold water.

“But I’m still alive and I’m able to do lots of things, so this isn’t a sob story.

"I want to use the marathon to inspire others and show them that the future doesn’t have to be bleak.

In September 2009, Rich Martin was had acute lymphoblastic leukaemia diagnosed, for which he needed a bone transplant to survive.

Having had the transplant in January 2010, he began to have complications and developed graft vs host disease, which means his transplant cells are attacking his body.

The condition has made his hair fall out, his skin fragile, and left him with an inability to sweat or cool down properly.

He must have between three and five hours of treatment at the Royal Marsden Cancer Hospital twice a month to try to manage the symptoms.

During the 26.2mile-run through central London on April 22, Mr Martin will be accompanied by his wife Rosie, a doctor, who will monitor his progress.

He will also publish live updates on Twitter, in which he tweets as @pluckyrich.

For details on donating visit: justgiving.com/themmartins.

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