According to NASA, last month was the hottest June documented in the past 139 years. And the National Weather Service forecasts record highs, at potentially deadly levels, through the coming weekend. How is climate change related to the extreme heat, and how can individuals and governments prepare for more days of it? William Brangham talks to Astrid Caldas of the Union of Concerned Scientists. Stream your PBS favorites with the PBS app: to.pbs.org/2Jb8twG Find more from PBS NewsHour at www.pbs.org/newshour Subscribe to our YouTube channel: bit.ly/2HfsCD6 Follow us: Facebook: www.pbs.org/newshour Twitter: www.twitter.com/newshour Instagram: www.instagram.com/newshour Snapchat: @pbsnews Subscribe: PBS NewsHour podcasts: www.pbs.org/newshour/podcasts Newsletters: www.pbs.org/newshour/subscribe