From the Northeast to the Midwest, Americans are in for another day of scorching temperatures.
Excessive heat is causing high customer demand for electricity in the East, leading to overstressed power grids and significant outages.
Businesses shut down in Providence, R.I., where 400 customers lost their electricity at the start of the workday.
"We had a couple little flickers. We didn't think anything of it and then all the sudden there was no electricity," Cecile Turgeon, with Bayada Home Healthcare, said.
The power company says an electrical failure in the lines beneath the sidewalk caused the outage. Bayada Healthcare office workers worried about the loss of work.
"I don't know what's left on my computer. Hopefully it's all saved," employee Bob Cardin said.
Some eastern cities distributed free water and ice. Hospital emergency rooms are seeing an increase in heat-related illnesses.
"I feel like I'm going to explode. It's so hot," Chicago runner Andres Arango said.
Medical experts say prolonged excessive heat can be dangerous to your health because the body doesn't get a chance to cool down. That can lead to high blood pressure, heart failure, and heat stroke.
Young children are especially vulnerable since their body temperature can rise three to five times faster than an adults.
"If you are at a playground, take your hand, slide it down. If it's hot for you to the touch, it's too hot for your child to play," Allyson Fulton, a child safety coordinator with Safe Kids Pennsylvania, advised.
The elderly are also at risk. Free fans are being handed out to them and children in Raleigh, N.C.
While the priority is to keep people healthy and cool, pets are also a concern.
"If they are overheated, you need to hose them down and get them to a vet right away," Page Wages, a veterinarian with CareFirst Animal Hospital in Raleigh, N.C., said.
Meanwhile, in the western United States, it's not just the heat that's raising concerns. Drought is also a worry. A lack of rain is raising the potential for wildfires. The fire season began two months earlier because of dry conditions.
Thousands of Californians have been ordered to evacuate their homes. A fast moving wildfire has already consumed 14,000 acres.
"This type of behavior you're seeing right now is what we'd typically be seeing August through September," U.S. Forest Service spokesman Chris Gaulding said.
This year's wildfire season is on pace to become the deadliest in U.S. history.