Could global warming make some states uninhabitable? With parts of the US sweltering in record-breaking heatwaves, the Americast team wonders whether cities like Phoenix in Arizona can continue to survive by the end of the century.Meanwhile, Sarah enjoys cooler temperatures in Colorado and catches up with the UK Foreign Secretary James Cleverly at the Aspen Security Forum.And Hollywood strikes have held up the Barbie film's press tour, but could politicians learn a thing or two from its internet-breaking marketing campaign?HOSTS: • Justin Webb, Radio 4 presenter • Sarah Smith, North America editor • Marianna Spring, disinformation and social media correspondent • Anthony Zurcher, North America correspondentGUEST: • James Cleverly, UK Foreign SecretaryGET IN TOUCH: • Send us a message or voice note via WhatsApp to +44 330 123 9480 • Email Americast@bbc.co.uk • Or use #AmericastFind out more about our award-winning “undercover voters” here: bbc.in/3lFddSF.This episode was made by Daniel Wittenberg, with Rufus Gray, Natasha Fernandes and Catherine Fusillo. The technical producer was Dafydd Evans and the sound designer was David Crackles. The editor is Jonathan Aspinwall.