Forecasters say temperatures should be cooling in the vast section of the country that's been under a heat wave, but that still means temperatures in the 90s.
Yesterday, cities from the Midwest to the East Coast registered highs above 100 degrees.
And the heat is being blamed for at least 35 deaths.
In suburban Indianapolis, a 4-month-old girl died and a 16-month-old was hospitalized in separate incidents.
Both children were found trapped in cars during near-record 105-degree heat.
Deaths have also been reported in Illinois, Maryland, Ohio, Pennsylvania, Tennessee and Wisconsin.
The heat also is doing damage to infrastructure, buckling highways and causing rail lines to kink.
Thunderstorms are ushering in cooler temperatures in many areas.
But in New Jersey last night, a line of strong, fast-moving storms knocked out power to nearly 70,000.