CBS World News Roundup, 7/19

CBS World News Roundup
Friday, July 19th
A brutal heat wave is scorching a huge swath of the nation, with nearly 200 million American dealing with triple-digit temperatures or feels like. President Trump says a U.S. warship has downed an Iranian drone. And an embattled congresswoman gets a hero's welcome in her home state. Correspondent Steve Kathan has the CBS World News Roundup: