year. so far across the south and the eastern part of the united states, we couple the heat and humidity, there's no escaping it. >> reporter: how hot is it? >> yesterday, the asphalt tripped at 160. >> reporter: temperatures that can scald in a meat of seconds. >> there's no shade. no place to hide. >> reporter: whether you work or play in the sun there's no escape. across much of the country, temperatures and heat indexes shot well into the triple digits. >> with the oil, you know it's hot. >> reporter: pushing people and power grids to the limit. in arkansas, officials say the brutal heat buckled concrete and firefighters were busy with more than a dozen wildfires. >> it's pitiful. it's hard on us. hard on the grass. it's just too hot. >> reporter: water lines burst in tulsa. and in the nation's capital, officials cut the speed of commuter trains in fear that the metal tracks might bend.