How do you keep food cold?

Up to 40% of food in Africa and India is wasted because of a lack of what's called "the cold chain" - the infrastructure keeping food chilled and fresh, from farm to fork. Many small-scale farmers have no access to any kind of refrigeration, meaning they're losing income and wasting food that could otherwise be sold.Devina Gupta meets the entrepreneur who is building pay-as-you-go solar powered cold rooms in India, and hears from farmers, traders and experts on how we can keep food cold as the population grows and the planet warms up.(Picture: A farmer carries a crate of mangoes from an orchard on the outskirts of Bangalore. Credit: Getty Images)Presenter: Devina Gupta Producer: Lexy O'Connor