The Cook County medical examiner's office Sunday added eight more people to its list of confirmed heat-related deaths, bringing the total in the county, which includes Chicago, to 18, the Chicago Tribune reported.
The total included 100-year-old Lucille Griffith, who died of heart disease and heat stress. The Tribune said she was found in her home with a body temperature of more than 107 degrees.
Maryland and Virginia each reported 10 deaths so far, and in St. Louis, in the center of the sweltering, three people had died, The New York Times reported. WMC-TV, Memphis, reported three people also had died in Shelby County in Tennessee, and the Lancaster Eagle Gazette reported three had died in Licking County in Ohio.
The Indianapolis Star reported at least five people had died in Indiana, including 4-month-old girl left in a car during 105-degree heat, a 92-year-old man was found inside his Marion County home and a 54-year old man was found outside near his residence in extreme heat.
The National Oceanic and Atmospheric Administration reported there had been more than 3,500 U.S. high temperature records broken from June 30 through July 6, Accuweather.com said.
National Weather Service meteorologist Katie Garrett told the Times a stubborn high pressure system over the central and eastern parts of the country is keeping back usual flows of other weather systems that would bring cooling.
As cities and town issued alerts and encouraged residents to seek shelter in air-conditioned public buildings, there were reports of roads and highways melting and buckling in the heat.
Train travel throughout the region was also affected, the Times said. A train outside Washington derailed Friday after tracks expanded, forcing rail officials to order a reduction in speed limits, the report said.
The heat wave also spawned violent electrical storms in the Northeast June 29 that knocked out power to more than 4 million customers.