The celebrities taking part in this year’s Comic Relief challenge have been warned to look out for deadly snakes as they prepare to trek across the Kaisut desert.

The nine famous faces, including TV presenter Dermot O’Leary, singer Craig David, presenter Lorraine Kelly and Strictly Come Dancing champion Kara Tointon, embarked on a three hour acclimatisation trek on Sunday, ahead of the start of their journey on Monday across one of the world’s most inhospitable deserts – the Kaisut Desert in northern Kenya.

As well as testing out their boots and rucksacks they also practised helping Radio 4 presenter Peter White, who is visually impaired, pick his way through the rocky terrain.

The team, which includes impressionist Ronni Ancona, actress and presenter Nadia Sawalha and radio presenter Scott Mills, will cover 100 kilometres across the barren desert in five days and face scorching temperatures of up to 40C.

Once they had arrived back at camp the trekkers were given a talk on the deadly creatures they might encounter, such as the Black Mamba snake and the fast-moving Camel spider.

Dermot said: “We’re all ready to go now. We’ve had a practice walk to try and get used to the heat, but it’s going to be very tough – we all know that. The snake and spider briefing was interesting to say the least! It’s safe to say that we will be watching where we tread.”

They previously arrived in the barren region on an eventful flight from Nairobi, which saw worried Olly Murs comforting Lorraine as the small aircraft pitched left and right before it touched down on a grass landing strip.

During the trek, the team will lead a caravan of camels which will be carrying their camping gear and other equipment needed for the journey.

Due to the heat and the gruelling task, experts have estimated that each member of the team will burn around 8,000 calories a day.

The BT Red Nose Desert Trek will raise money for Comic Relief projects which benefit deprived people across Africa and in the UK.