Nine celebrities including Dermot O’Leary and Lorraine Kelly are set to trek the BT Red Nose Desert Trek.

The team, which includes Craig David, Scott Mills, Olly Murs, Nadia Sawalha, Kara Tointon and Peter White, will tackle the trek, dubbed “the toughest physical challenge of their lives”.

The team will hike 100 kilometres of desert in five days while enduring temperatures as high as 100 degrees Fahrenheit. The celebrities will trek over mountains, through bush and across desert.

Trekkers are expected to burn an incredible 8000 calories per day and lose up to 20 litres of water.

126 species of snake live in the desert including the deadly Black Mamba and the Puff Adder.

Cash raised will go towards Comic Relief projects, including those that help prevent thousands of people in Africa going blind or contracting eye conditions like trachoma.

A Comic Relief spokesman said: “Throughout the course of the trek, the celebrities may meet many people who are losing their sight and need urgent eye care.

“They’ll be spreading the word about a special eye care camp that they’ll reach on the last day of their trek, where people they’ve met along the way will get treatment that could save their sight.”