Paramedic Ray Edensor has revealed the latest challenge in his three-year quest to raise £200,000 for children's charity Dreams Come True.
The Parathon 2005, which could prove to be the ultimate fitness and endurance test, will see Ray run - wearing a decontamination suit - from Hanley in Stoke-on-Trent, Staffordshire, to London, starting on April 7.
Once he reaches the capital, which will involve him running over 200 miles, he then plans to take part in the London Marathon, while still wearing the suit.
Decontamination suits are designed to be worn by paramedics working in hazardous environments and Ray will wear the suit for up to 23 hours a day, even sleeping in it, during his run.
He will be monitored and supported throughout by a team of dedicated fellow paramedics and expects to lose around two stones in weight.
To warm up for his latest challenge Ray will be running in the Stafford half-marathon on March 20.
He said: "This may seem like a daunting task but it really becomes insignificant when compared to the future facing many of the kids helped by Dreams Come True."
The Staffordshire ambulance paramedic has already raised almost £100,000 by running what is believed to be a record number of miles in sponsored marathons.
Last year he was named the Children's Champion by Barnardo's. Anyone who wants to offer help, such as sponsorship, can contact Ray on 01785 211105.