They had prepared themselves for the searing sun and host of deadly insects.
But it seems the main hurdle facing the nine celebrities on the Comic Relief trek is the gruelling fitness regime.
They planned to raise money for people in Africa and the UK by crossing 100 kilometres of Kenya's Kaisut Desert in just five days.
But with day four approaching the famous faces - including Lorraine Kelly, Kara Tointon and Dermot O'Leary - are suffering from the harsh conditions.
CLICK ON PHOTO FOR GALLERYAlthough plagued by blisters, sore muscles and exhaustion, the team has managed to reach the halfway point of the trekking challenge and are determined to continue.