In the stifling subway tunnels, there was no air conditioning on three cars of the train Sayed Bukhari rode into Manhattan.
"People were crying," Bukhari said.
The National Weather Service posted heat advisories and warnings from Maine to Oklahoma. Triple-digit temperatures were forecast Wednesday along the East Coast as far north as parts of Maine and New Hampshire.
And don't look to the nighttime for any relief.
Research shows the United States in recent years has been sweltering through three times more than its normal share of, government weather records show. And that is a particularly dangerous trend. From 2001 to 2005, on average nearly 30 percent of the nation had "much above normal" average summertime minimum temperatures, according to the National Climatic Data.
The temperature was already above 80 before dawn Wednesday at Nashua, N.H. New York's LaGuardia Airport still had 92 degrees at midnight and eased only to 86 degrees by 6 a.m., the National Weather Service said. In the heart of crowded Manhattan, the low at Central Park only got down to 83.
New York City Mayor Michael Bloomberg declared a heat emergency, CBS News' The Early Show weatherman Dave Price reports.
"It feels like we're having a barbecue in Zimbabwe right now," a commuter told Price.
Equipment problems and stormy weather caused scattered power outages during the night in parts of New England, shutting off fans and air conditioners, utilities said.
Electricity usage in the six-state New England region could top 28,000 megawatts Wednesday, breaking the one-day record of 27,395 megawatts set just two weeks ago, according to Erin O'Brien, a spokeswoman for ISO New England, which oversees the region. The demand Tuesday was just shy of the record, she said.
The hot weather brought its share of troubles Tuesday, putting animals in jeopardy, disabling cars and prompting New York to turn off lights atop the Empire State Building.
CBS News correspondent Bob Orr reports that 1,200 residents on Chicago's South Side were evacuated from high-rise buildings by the hundreds on Tuesday, one day after the power went out to 20,000 customers. Illinois officials blamed three deaths on the heat.
A 15-year-old high school football player died in Georgia, one day after collapsing in the heat at practice, and the heat was suspected in the death of a 75-year-old woman in Wisconsin who kept the air conditioning off to save money.
To the north and west, some areas had started to enjoy a break from the heat. Hayward, Wis., cooled to 70 on Tuesday, down from 104 degrees on Monday.
Elsewhere, however, by mid-afternoon Tuesday the temperature in Chicago was 100, Baltimore reached 99 and Washington hit 97, though the humidity made it feel like 107. Highs of 100 in Newark, N.J., and 97 in Atlantic City, N.J., tied records. In Manchester, N.H, it reached 95, tying the record for the date set in 1933.
Utilities said customer demand for power reached or exceeded all-time record highs.
With a disastrous 10-day power outage in one borough still fresh in memory, thermostats at city offices in New York City were set at 78, up from the usual 72. Lights were turned down on the Empire State Building and the Chrysler Building, as were the lights illuminating the George Washington Bridge, the Brooklyn Bridge and other spans.
Farmers used fans and cold showers to keep their cattle cool, but at least 25,000 chickens died of the heat at an Indiana when electricity was shut off so firefighters could fight a blaze at an adjacent building.
The American Automobile Association's Mid-Atlantic division handled 7,400 calls for assistance from Monday afternoon through Tuesday evening, a 37 percent rise over normal summer call volume.
"That's about comparable to what we get in a major snowstorm," said John B. Townsend, an AAA spokesman. Many were for overheated vehicles, hoses, belts breaking down and cracking and tires blowing out on the hot asphalt.
In Maine, Aquaboggin Water Park in Saco prepared for big crowds on Wednesday, bringing in cases of bottled water for customers and calling in extra staff.
"We're gearing up for it," general manager Sally Christner said. "Nobody else is excited about the heat, but we are. This is a great place to be when it's hot."
The extreme heat is also prompting Red Sox officials to take some extra precautions for fans and players at Boston's Fenway Park this week.
Dozens of fans were treated for heat-related symptoms during Tuesday night's game against the Cleveland Indians. Team officials set up a giant water mister for fans, handed out ice packs and put extra medical personnel on duty. Beer sales were also cut off one inning earlier than usual. Similar precautions will be in place for tonight's game.
The Red Sox are also making afternoon batting practice optional for their players.