About this programme
3/10. The team heads to Death Valley in California - one of the world's hottest places, with the mercury reaching 57C. The pair endure a test to work out which colour is the best to wear in heat, Clare finds out what it's like to go to school in searing temperatures, and Leo becomes one of the first people to climb the area's hidden canyons. Later, he completes a section of the Badwater Ultramarathon - a race five times longer than the London Marathon.