Amidst rising Covid infection levels, we're looking at one alarming threat to health services from Brazil to Egypt - a lack of medical oxygen. Hospitals have been reporting running out altogether, with some critical care patients dying as a result. Where does medical oxygen come from and what is the problem with its supply? Ed Butler hears from Mike Grocott, professor of anaesthesia and critical care at the University of Southampton, as well as gas industry consultant John Raquet. Also in the programme, Pakistani comedian Shafaat Ali tells us what it’s like for patients forced to source their own oxygen to survive. (Picture: A man holds an oxygen tank in Manaus, Amazonas State, Brazil. Credit: Getty)