In the run-up to Red Nose Day 2009 (on 13th March), Radio 1's Chris Moyles, Fearne Cotton and seven other brave celebs head to Africa for one of the biggest challenges of their lives.
Joining Chris and Fearne will be Cheryl Cole, Kimberley Walsh, Alesha Dixon, Ben Shepherd, Ronan Keating, Denise Van Outen and Gary Barlow.
They'll be walking for seven days to the top of Mount Kilimanjaro in Tanzania to raise money for Comic Relief - and they want your help.
Music 4 have produced the theme tune for all the coverage of The Big Climb on BBC Radio 1. In addition, while Chris climbs the mountain, Vernon Kay will present the Radio 1 Breakfast Show and we've customised Chris's jingles to reflect this on-air change.