Dara O'Briain is among the stars who are taking on a difficult challenge traversing the Zambezi River in Africa for Comic Relief.
The Irish comedian will be joined by Jack Dee, Mel C, Chelsee Healey, Grey James and Phillips Idowu as they take on a 111km journey across the river in canoes, white water rafts and dugout boats.
The group will be paddling up to eight hours a day for five days as they negotiate the African river, facing rapids known as The Washing Machine, Oblivion and Gnashing Jaws of Death on their way to the world's largest waterfall, Victoria Falls.
The challenge, which is called BT Red Nose Challenge: Hell and High Water, will involve the stars camping on cliff-tops and riverbanks en-route to their final destination.
Armed guards will accompany the group to protect them from wild animals as they sleep.
The journey is being staged ahead of this year's Red Nose Day on March 15 and hopes to raise €1.2 million for the cause.
O’Briain said: “When I was first asked to do this challenge, I did a quick Google search of Zambezi rafting but after the 10th page of people being instantly flung into the water I turned off the computer.
“But lives can be changed if people put their hands in their pockets in exchange for our misery so that sounds like a fair deal.”
Mel C commented: "It’s going to be tough. It’s going to be physically and emotionally demanding, but we’ve all got each other and hopefully we’ll be able to get through it.”
The proceeds will be used to help educate children in Zambia.
The stars can be sponsored at rednoseday.com/zambezi.