Do you reckon you could walk 100 kilometres across a desert in 100 degree heat? Well that's the challenge ahead for these nine celebs!
For this year's Comic Relief the challengers have just one week to trek across the Kaisut desert in northern Kenya. Olly Murs seems pretty relaxed about it all...
He's joined by Strictly Come Dancing champ Kara Tointon who will be hoping that her ballroom skills will help her cross the desert in style!
Dermot O'Leary has always been able to keep his cool in front of the judges on the X Factor stage, but will he be able to handle the heat in the desert?
Dermot and Kara are joined on the trek by Radio 1 DJ Scott Mills and Breakfast TV favourite Lorraine Kelly. Dermot's packed a lot of luggage!
The gang are doing the trek to raise cash for Comic Relief and to fund projects like this eye clinic.