Dancing On My Own (Tiesto) Calum Scott
David Walliams has been forced to put on a wetsuit despite hoping to swim the length of the Thames in just his trunks.
The Little Britain star's skin started to turn blue during his 140 mile charity swim.
His trainer made him put on the suit at the first stop, to make sure he doesn't develop hypothermia.
David said: "The first section of the swim has really shocked me. The water is two degrees colder than when I swam the Channel, just 15 degrees."
Walliams's wife, model Lara Stone, saw the comedian off with a kiss in front of a large crowd who lined the river bank at Lechlade, Gloucestershire.