It has been another scorcher in much of the country, with several cities once again hitting record highs.
For example, it hit 105 degrees in Joplin, Missouri. Trenton, New Jersey and Austin, Texas, both had highs of 104.
Also, more than 20 heat-related deaths have been reported.
CBS News correspondent Elaine Quijano reports that millions of Americans tonight are wilting under this incredible heat wave that, in a word, has been unforgiving.
Saturday brought no relief from the relentless heat.
"You can hardly breathe. It's very tough," says New Yorker Leroy McKee.
Some New York City residents took advantage of city cooling centers as sidewalks outside sizzled. The reading off the sidewalk outside one such center said the ground clocked in at 147 degrees.
"We're getting heated above and below and all around, in fact, every direction," says Stuart Gaffin, a Columbia University climate researcher.
Cities tend to hold on to heat, making people there more vulnerable and miserable, Gaffin says. Even in the shade, the sidewalk was still 107 degrees.
It takes a long time for concrete, granite, and brick to cool off, so that's one contributing factor at night.
"(Cities) don't get much relief at night, and in fact temperatures like this are almost dangerous at night, you know, 80 and above," Gaffin says.
Across the country, heat advisories have been posted in 27 states, and excessive heat warnings are up in 18 states.
However, not everyone's complaining. Ice deliveryman John Natuzzi says he prays for hot days like this.
"We need this weather to keep us afloat. Basically if we don't have a good summer, it's gonna be a long winter for us," Natuzzi says.
In northern Virginia, where the mercury hit 100 degrees, the extreme heat didn't stop a Civil War re-enactment. Men wearing wool uniforms marked the 150th anniversary of the Battle of Bull Run.
"Your body after awhile in the wool kinda gets a little acclimated to the heat," one re-enacter says.
Forecasters say tomorrow will be slightly cooler in some parts of the country, like the Mid-Atlantic and the Northeast, thanks to a blast of cool air from Canada. But they warn, the dome of heat that enveloped much of the country could re-build by the end of next week.