Summary: The next time you open your fridge, take a second to behold the miracles inside of it: Raspberries from California, butter from New Zealand, steak from Nebraska. None of that would have been remotely possible before the creation of the cold chain. The cold chain is the name for the end-to-end refrigeration of our food from farm to truck to warehouse to grocery store and ultimately to our fridges at home. And it’s one of the great achievements of the modern world. On today’s show, Nicola Twilley, food journalist and author of Frostbite: How Refrigeration Changed Our Food, Our Planet, and Ourselves, tells us the story of how our world got cold, and what that’s meant for the economy.  We’ll hear about two pioneers of cold: The cheapskate meat baron Gustavus Swift, and the train-hopping chemist Polly Pennington. And we’ll take a look at whether all this refrigeration might have created some new problems. Subscribe to Planet Money+Listen free: Apple Podcasts, Spotify, the NPR app or anywhere you get podcasts.Facebook / Instagram / TikTok / Our weekly Newsletter.Today’s episode of Planet Money was hosted by Nick Fountain and Alexi Horowitz-Ghazi. It was produced by James Sneed and edited by Keith Romer. It was fact-checked by Sierra Juarez and engineered by Valentina Rodríguez Sánchez. Alex Goldmark is Planet Money's executive producer.