Even before summer began, there were extreme heat waves and new heat records throughout the Northern Hemisphere, and the forecast calls for a hotter-than-normal summer in much of the U.S. Scientists say climate change is accelerating and intensifying these kinds of heat waves. It's taken a while for some TV weather men and women to make these connections, but that's changing. Miles O'Brien reports. Stream your PBS favorites with the PBS app: https://to.pbs.org/2Jb8twG Find more from PBS NewsHour at https://www.pbs.org/newshour Subscribe to our YouTube channel: https://bit.ly/2HfsCD6 Follow us: TikTok: https://www.tiktok.com/@pbsnews Twitter: http://www.twitter.com/newshour Instagram: http://www.instagram.com/newshour Facebook: http://www.pbs.org/newshour Subscribe: PBS NewsHour podcasts: https://www.pbs.org/newshour/podcasts Newsletters: https://www.pbs.org/newshour/subscribe