How much heat do you lose from your head?
Is it true that 40% of your body's heat loss comes from your head?
Every winter its the same, someone will tell you to put a hat on to save your body from losing all of its heat. But how much heat do you actually lose from your head? We take you on a journey from arctic conditions to a hot tub in Canada to explain why there might actually be more than one answer...
Presenter: Tim Harford
Producer: Leoni Robertson and Lizzy McNeill