flames. these hospital hallways dark after a transformer blew there. in six hospitalized from heat exhaustion. people have to make smart decisions. reporter: in philadelphia the city has activated its emergency heat line. nurses online to take calls. the heat index is the 99 degrees. this is an area where a fan s not going to help you. reporter: already this year ten children have died after being left it in hot cars. that s why these good samaritans in kansas busted over this car window to save a child who was accidently left in the scorching heat. the child is okay, the parents cited for child endangerment. and in emergency rooms like this one, doctors remind us that kids and elderly are among the most