A record heat wave is bearing down on nearly 1.8 million people from North Carolina to New Jersey who are sitting in the dark after a storm ripped through the East Coast knocking out power last week.
More than 1 million homes in seven states remain without power after Friday's freak storm and officials fear the death toll, already at 22, could rise because of the sweltering heat.
Across the U.S. today, temperatures pushed well into the 90s. Five cities -- including Chicago, Detroit and Kansas City -- are on track to have their hottest Fourth of July ever.
Washington's Pepco power company was one of the hardest hit by last weekend's violent storms. More than half a million people in the area are still without power.
Spokesman Clay Anderson said some customers might not have power until Friday, but the utility has called in crews from as far away as Canada and Florida to help.
"We have brought in crews from both New Brunswick and Quebec, Canada, Florida, South Carolina. Other utilities from Illinois to New Jersey are doing the same," Anderson said.
Several hundred traffic lights in and around Washington created traffic snarls Monday. Crews worked to remove downed trees that blocked roads so people can get to work.
When it comes to getting the power running again, all utilities take a top-down approach that seeks to get the largest number of people back online as quickly as possible.
First, crews repair substations that send power to thousands of homes and businesses. Next, they fix distribution lines. Last are the transformers that can restore power to a few customers at a time.
Unlike hurricanes, which take several days to reach land with warning, this storm hit quickly and swiftly through eight states with no warning, forcing crews to scramble in its aftermath.
"We're rebuilding our system, basically, that's the way you got to think of it," Dominion Virginia Power's Ken Barker said.
The Westfield Montgomery Mall in Maryland has turned into a relief center with hundreds lining the walls looking to plug lap tops and phones into outlets.
The weather will do little to cooperate as crews work to get power restored. From the Central Plains to the Mid-Atlantic, it's going to stay hot. The East Coast got a bit of reprieve from the heat Monday but forecasts through the week show temperatures spiking again to the 90s and 100s.
July is picking up right where June left off when 3,167 heat records were broken in the United States. On Monday, 45 states had 90 or above temperatures.
ABC News' Ginger Zee and Andy Field and The Associated Press contributed to this report.