Holly Willoughby and Lee Mack follow eight celebrities as they give up their warm cosy lives to live in the Italian mountains in sub-zero conditions. There they face a series of daunting cold challenges designed to push their minds and bodies to the limit. Their guide is the record-breaking extreme athlete Wim Hof - aka the Iceman - who believes that embracing the cold can change lives for the better. The celebrities - Patrice Evra, Gabby Logan, Alfie Boe, Tamzin Outhwaite, Owain Wyn Evans, Dianne Buswell, Professor Green and Chelcee Grimes - are all taking part for different personal reasons and are hoping they will emerge from the experience feeling happier, healthier and stronger. Can the cold change their lives forever, or will the freezing conditions become too much to bear?