Jessica Blue stood barefoot in the fountain at Manhattan's Washington Square Park, her clothes and hat getting drenched with cool water as the temperature neared 100 degrees.
"I was out shopping, but I couldn't take it any more," the 54-year-old said Tuesday. "Better cold water than sweat. I'm sick of sweating."
Relief was on the way, at least for the northeast, on Wednesday with a cold front expected to lower temperatures to the mid-80s.
Elsewhere, though, the sticky, steam bath weather was hanging on. The temperature was expected to top 100 in Arkansas, Nebraska and other parts of the Midwest and southern Plains each day through the end of the week.
"For it to be 100 degrees on the East Coast and 100 degrees in Salt Lake City, the widespread heat is what makes this particular hot spell unusual," Penn State University meteorology professor Fred Gadomski told CBS News.
The soaring heat had already been blamed for 12 deaths, from South Dakota, where a hiker collapsed, to Pennsylvania, where a 23-year-old man with cerebral palsy died Tuesday after apparently being left in a sweltering van, authorities said.
With the rising temperature, utilities faced record peaks for electricity demand as people turned up their air conditioners and officials pleaded with them to conserve.
Blasting air conditioners sent power consumption surging. Records were set all over the country — Californians used 46,000 megawatts, the most ever, CBS News correspondent Trish Regan reports.
The first signs of a reprieve hit Vermont Tuesday afternoon with a bang: Heavy thunderstorms swept across parts of the northeast, knocking out power to tens of thousands of utility customers.
The storms, coupled with the hot weather, were the likely causes of an outage that left about 9,900 Consolidated Edison customers without power in and around New York City, spokeswoman D. Joy Faber said Wednesday. Almost 26,000 customers of New York's Long Island Power Authority were still without power, according to the utility's Web site.
At least 60,000 customers in New Jersey and about 365,000 in Pennsylvania also lost power. A 44-year-old woman was killed Tuesday when lightning hit her in a Detroit park.
The storms also sparked a fire at Rhode Island's Port of Providence when lightning struck a dock, sending large plumes of smoke and fireballs into the air.
The thermometer in New York peaked at 95 degrees in Central Park on Tuesday and 100 at LaGuardia Airport, the National Weather Service said. The hottest place in the nation was Needles, Calif., which hit 109.
While it lasted, the heat caused plenty of headaches on the East Coast.
An electrical cable failed at LaGuardia, knocking out power to one terminal and part of a second terminal for several hours. American Airlines canceled 45 flights, and Delta canceled 11 flights.
Amtrak travelers riding between Washington, D.C., and New York on Tuesday evening experienced delays of at least an hour that conductors blamed on the extreme heat, which requires trains to travel at reduced speeds.
Relief could not come soon enough for many people working outdoors.
"If I see sprinklers or hydrants, I just drench myself," said New Haven, Conn., letter carrier Ceferino Roman, who walked his route in 20-minute intervals, taking breaks in between. "This is the worst."
On Long Island, auto mechanic Rick Baymack said he was trying hard to stay cool while at work.
"Plenty of cold water," he said. "We stay in the shade, we keep the hoods closed on cars as long as we can, before the car comes in the shop we let it cool down."
Utilities set records for electricity use, and health departments advised people without air conditioning to cool off in senior centers, malls and movie theaters.
In New York, Mayor Michael Bloomberg reminded residents to conserve electricity. He directed City Hall to do its part: Only natural light filtered into the rotunda Tuesday, and some passageways and rooms were dark.
"There's plenty of light coming through the windows, you don't have to keep the lights on, and if everybody did some of that, that would really save some electricity," the mayor said.
The Long Island Power Authority set a record for peak summer demand two days in a row, with 5,426 megawatts of electricity used Tuesday, enough to power more than 5 million homes on a normal day. Peco Energy Co. said the Philadelphia region also hit a high at 8,653 megawatts. The entire New England regional power grid set a record at 27,374 megawatts, said Ken McDonnell, spokesman for grid manager ISO New England.
The heat that has stifled much of the nation since late last week has contributed to the deaths of at least 12 people, including three in the Chicago area, two in the Philadelphia area, two in Oklahoma City, two in Arkansas and one each in Indiana, South Dakota and Tennessee.
The case in South Dakota was a 52-year-old Ohio woman who died Sunday of apparent heat exhaustion and dehydration while hiking the 100-plus degrees of Badlands National Park, officials said Wednesday. Two hikers also died in the heat of the southern Utah desert, but the causes of death had not been determined Wednesday.