Updated at 2:12 p.m. ET
NEW YORK - Americans withered under yet another day of searing sun Friday as a heat wave spread in earnest into the urban core of the Northeast, while warnings about excessive heat stretched from Kansas to Maine and the Carolinas.
Across the nation, 40 states are experiencing temperatures of more than 90 degrees, CBS News correspondent Whit Johnson reported on "The Early Show." The number of locations that have either tied or broken daytime records this month is 1,279. At least 22 people have died of heat-related causes. Oklahoma City saw its 29th day of 100-degree heat Thursday.
Temperatures hit 100 in New York's Central Park and in Newark and Teterboro, N.J. The National Weather Service said the smoldering humidity made those temperatures feel like 116, 114 and 110, respectively.
It's enough to test the patience of a saint.
Taking her morning walk with temperatures already soaring near 90, Sister Elizabeth Ann Hughes of St. Thomas Aquinas Roman Catholic Church in Philadelphia offered her simple strategy go out only when it's relatively cool and stay in the air conditioning when it's not.
"I walk in the shade and get out of the sun before 10 a.m.," she said.
In New York, people looking to beat the heat also were thwarted by warnings urging them to avoid some city waterways after a wastewater treatment plant disabled by fire began spewing millions of gallons of raw sewage into the Hudson River.
Officials cautioned against swimming and bathing at four beaches in the city boroughs of Staten Island and Brooklyn, especially for people with medical conditions.
Beesham Nanan, 53, was drinking coffee in an air-conditioned fast-food restaurant before starting his shift as a limo driver. He often has to drive clients to their destinations and then wait in the car. He tries to park somewhere where he can turn the car's air conditioning on, but it's risky. "You're not supposed to have the engine on in the city," Nanan said. "It's a big fine."
Across the country, emergency room visits were way up, according to public health officials, mainly because of people suffering from heat exhaustion and heat stroke.
The weather is suspected of contributing to a number of deaths nationwide. At least six more fatalities were reported Thursday, including a Michigan restaurant cook who suffered a heart attack after being sent home from his job and a teenage boy who drowned while swimming at summer camp in the same state.
In Chicago on Thursday night, hundreds of children and more than a few adults cavorted in a shallow pool of the Crown Fountain in Chicago's Millennium Park. Temperatures hovered around 90 degrees in the park, about half mile from the shores of Lake Michigan.
Christopher and Renee Mickles said they came out in the evening to give their 3-year-old a little exercise after being cooped up in their air conditioned house.
"It didn't cool off, but at least the sun isn't out," he said.
A Pittsburgh man working on the roof of his cousin's home Thursday found himself stuck for nearly two hours because of the hot tar he'd been using. Lamont Robinson said the slick tar kept him from climbing to safety after he slipped. He said he was "baking like a turkey" before his rescue. Temperatures were in the low-90s.
In Connecticut, a dozen Girl Scouts were treated for heat-related problems at a scout camp.
None of the girls required hospitalization, but New Fairfield First Selectman John Hodge says they spent Thursday night in the camp's cafeteria after workers brought in industrial fans to help cool them off.
Philadelphia's public schools canceled summer classes Thursday and Friday, while Allentown to the north waived fees at its public pools.
Civil War buffs in Virginia said the weather would not deter them from holding a re-enactment commemorating the 150th anniversary of the Battle of Bull Run.
But one thing they wouldn't be able to replicate is the temperature. In July 1861, when the North and South clashed in the Civil War's first major battle, temperatures were in the 80s.
All of New Jersey, save for a sliver of its shoreline, was under an excessive heat warning. The heat forced Monmouth Park to cancel its horse racing card and reschedule it for Monday, and some businesses were planning to shut down early on Friday.
"So far, so good," said Mary Goepferd, the external affairs officer for the state's Office of Emergency Management. "We're not hearing of many major problems, and people seem to be finding ways to cope with the heat. We're also thankful that senior centers and libraries have been welcoming people who don't have air conditioning."
The heat didn't deter the hundreds of people who lined up outside the Izod Center on Friday morning to audition for NBC's "The Voice." Temperatures were already in the 80s when doors at the East Rutherford center opened at 7 a.m.
Special dangers can come at night, experts warn, if the temperatures don't cool enough to provide relief.
While the current heat wave has recorded 12 all-time daily highs so far this month, it also has registered 98 all-time overnight highs, the National Oceanic and Atmospheric Administration reported at a briefing Thursday.