A man with a club foot is to take part in a marathon in Antarctica as part of a challenge to raise £50,000 for the hospital where he was a child patient.
Mr Tointon is set to run the Ice Marathon on 5 January
Mark Tointon, from Dorset, is to run in the Ice Marathon on 5 January for the Great Ormond Street Hospital.
His 7/11 Marathon Challenge - named because he has one size seven foot and one size 11 one - will see him take part in marathons on seven continents.
The 40-year-old was treated at the London hospital over a 16-year period.
Mr Tointon, from Broadstone, near Poole, said: "Even though technically I am considered to be disabled, I think of myself as "enabled' by Great Ormond Street Hospital.
"Without the treatment I received at (the hospital) I would not be able to lead the active life that I do.
"Running the 7/11 Marathon Challenge allows me to say thank you to the hospital for what they did for me."
To raise money for Great Ormond Street Hospital Children's Charity, Mr Tointon ran the New York marathon last November.
He also intends to undertake a number of other marathons across the globe before the challenge ends in November 2007.