Summary: Living in certain parts of a city can make the impacts of extreme heat worse. That's because of a phenomenon called the urban heat island effect. A recent report by the research group Climate Central showed that more than 40 million Americans live in these hot spots. William Brangham discussed what this means for those residents with Michael Mendez of the University of California, Irvine. PBS NewsHour is supported by - https://www.pbs.org/newshour/about/funders
