(CNN) -- Out of power since Friday, Bethesda, Maryland, resident Jacqueline Hirsch went to the library to seek relief from the heat, only to find hundreds of others had the same idea.
"If you need to charge your phone or you need Internet or anything, you show up here and it's literally a madhouse," Hirsch told CNN affiliate WJLA-TV on Monday.
People were sitting on the floor of the library, using every available outlet to charge their laptops and cell phones.
Some of the millions without power after deadly heat-driven storms struck the area Friday flocked to malls, libraries, pools and most any other public place with electricity to seek relief from a massive heat wave blanketing much of the nation.
"He's supposed to be in camp today, and he's not because his camp got canceled," said Pawan Dhingra, who brought his preschooler son to the library. "So we have no power, it's hot, we wanted air conditioning, charge my cell phone and ... hang out with my kid in a place that's comfortable."
As of Tuesday morning, about 1.37 million people scattered through 11 states, from Indiana to Delaware and Washington, had no electricity, down from about 1.8 million overnight -- and a peak of 4 million on Friday night and Saturday, just after the storms hit.
The total included 351,000 in West Virginia, 309,000 in Ohio and nearly 279,000 in Virginia, along with about 116,000 in metro Washington. Power and government authorities said some may not get electricity back until the end of this week.
For Tuesday, extreme heat warnings were issued for parts of Illinois, Indiana, Missouri, Kentucky, Ohio and Michigan, with the National Weather Service saying that those areas would be scorched with temperatures near or above triple digits.
Heat advisory warnings were also in place for a handful of states, including parts of Nebraska, South Dakota, Wisconsin, Minnesota and Iowa.
Cities and towns in the Midwest, Mid-Atlantic and Southeast have already endured temperatures in the high 90s and above 100 degrees since, in some cases, the middle of last week. It's all part of a system tied to the breaking or tying of more than 2,238 hot weather records nationwide between June 25 and Sunday, according to the National Climatic Data Center.
Frustrations were mounting for many.
Residents of Boone County, West Virginia, said Monday their region was among the hardest-hit, telling CNN affiliate WSAZ-TV they're not getting help.
"We have a pool and we have a generator, but a lot of these people have nothing," said Stacy Peters of the Prenter community. "It makes you want to sit down and cry."
She said, "I know they have a job to do and (power lines) are down everywhere, but you know what? Send somebody down here to check on us. Or set a cooling center up here for us or see if we need water."
The nearby community of Wharton set up a cooling center but said water and ice are in short supply.
"Ever since Saturday, we've had people -- 40, 50, 60 people -- waiting to get some relief and it's just not coming," said Carlos Jarvis of Wharton. "... People are in dire straits, really."
In Rockville, Maryland, members of the Brandon family attempted to escape the heat by sitting on their porch.
"Three windows I can open, (but) it doesn't help at all," Nick Brandon told WJLA on Monday.
"Today feels hotter than yesterday," said his father, Ivan Brandon. "We've figured out how to do it. We sit out here, we sit out back on the deck."
In Germantown, Maryland, crowds packed one of the few public pools with electricity.
"It's just great to get out of the heat. It's super hot without air conditioning in the house, so it's great to cool off in the water," Brian O'Keefe told WJLA.
And a mall in Wheaton, Maryland, looked like it was Christmas season instead of early July.
Matt Lloyd of Silver Spring spent several hours there with his children, WJLA said. "It's nice that there's still power here," he said.
At least 16 people were killed from Ohio to New Jersey in the derecho, a massive storm packing straight-line wind damage, while another three in North Carolina died in a second round of storms Sunday.
"It was the scariest thing I've ever been through," CNN iReporter Mark Cohen said from Mays Landing, New Jersey, where the storms damaged his property and knocked out power. "Just to give you an idea, it was somewhere between a movie and a disaster ride at a park."
Ken Mallette, executive director of the Maryland Emergency Management Agency, compared the damage to that seen after Hurricane Irene last year.
"We got a hurricane punch without a hurricane warning," he told CNN on Tuesday.
His agency is most concerned with 36 critical care facilities, such as nursing homes, that were operating on generator power, he said.
While the Pepco power company drew criticism from many in the wake of the outages, Mallette said the utilities' response "will be dealt with in an after-action issue."
For now, he said, "we're not going to be happy until we have every Marylander back online. ... We have zero tolerance. We want that power back on yesterday."
Effects of the storms lingered in many locations. In the Washington suburb of Fairfax County, Virginia, the 911 system -- which went down completely Friday -- was still not fully functional as of Monday afternoon, according to WJLA.
A Verizon facility in Arlington, Virginia, lost power as a result of the storm Friday, meaning 911 calls in Arlington, Manassas and Fairfax and Prince William counties did not go through, the station said.
In Prince William County, spokesman Jason Grant told WJLA that 911 calls began working again on Monday.
Sharon Bulova, Fairfax County Board of Supervisors chairman, said a regional task force will be appointed to determine what went wrong.
July Fourth celebrations were canceled in several Maryland locales, including Kensington, Germantown, Rockville and Gaithersburg, officials said. Bone-dry and hot conditions forced fireworks cancellations in other areas.
Traffic lights remain out in many hard-hit locales, including around the nation's capital, yet another reason for headaches.
"A lot of detours, a lot of lights that are out (and) some that are spotty," said Larry Simmons, a frustrated commuter in southern Maryland. "A lot of congestion, a lot of discourteous drivers."
For one driver in Wisconsin, the extreme heat caused a dangerous situation that was captured on video.
The heat buckled a stretch of highway in Chippewa County, creating a ramp on the road Sunday. Several cars were able to slow down before hitting the buckled portion of roadway, but then a sport utility vehicle hit the roadway and went airborne for some 15 feet before landing roughly back on the highway, CNN affiliate WQOW-TV reported.
The driver and passenger were taken to a hospital complaining of neck and back injuries and the highway was repaired, the station said.
"I was kind of shocked; you don't normally see that stuff in real life," said Theresa Reich, who videotaped the SUV on her phone.
CNN's Ashley Hayes and Devon Sayers contributed to this report.