A large swath of the U.S. suffered through another miserable day of sizzling temperatures and high humidity Monday — a deadly heat wave that had people cranking up air conditioners, scrambling to cooling shelters and running through sprinklers in the park.

Temperatures soared past 100 in several cities, and the National Weather Service (search) posted excessive heat warnings and advisories from Illinois to Louisiana and from Nebraska to the District of Columbia.

"It feels like basically just walking around in an oven," said 20-year-old McDarren Paschal as he mowed grass at Sinclair Community College (search) in Dayton, Ohio.

The blistering heat has caused numerous deaths this summer. In the Phoenix area alone, 24 people, most of them homeless, have died.

City workers in Chicago checked on elderly residents and shuttled people to cooling centers Monday, hoping to avoid a repeat of a disastrous 1995 heat wave that killed 700 people. Wilmington, Del., set up sprinklers in city parks so people could run through the spray to cool off. A social service agency in Oklahoma City handed out fans to elderly people who didn't have air conditioning.

Sherri Ball went to a cooling center in Peoria, Ill., because her window air conditioner couldn't keep up with the heat, a day after the mercury topped 100 degrees in the central Illinois city for the first time in a decade.

"It's hot and I can't breathe when it's real hot outside," said the 46-year-old Ball.

At least three deaths have been blamed on the heat in Missouri this summer, and authorities were looking into the death of a woman found Sunday in a home without air conditioning. Four people have died of the heat in Oklahoma, two of them young children left in cars, and at least three heat deaths have been tallied in New Jersey.

Some 200 cities in the West hit daily record highs last week, including Las Vegas, Nev., at 117, and Death Valley (search) soared to 129, the weather service said.

A break in the heat was on the way, at least for the Midwest.

A cold front brought rain Monday to parts of Iowa, Minnesota and Wisconsin, and was on its way to crossing Illinois, Missouri and Indiana on Tuesday, said Ed Shimmon, a weather service meteorologist in Lincoln, Ill. He said rainfall will likely be scattered, but still welcome in the drought-stricken region.

Demand for electricity to run air conditioners has hit near-record peaks from Southern California to the region served by the Tennessee Valley Authority. The load on generators caused a power outage in St. Louis County, Mo., where more than 900 customers were still without electricity Monday.

The heat was hardest on people who have to work outside.

"I try not to think about it," said Beatrice Gonzales, running a hot dog stand in Baltimore as the temperature neared 90.

"I guess you can never really get used to the heat, but you get tolerant of it," construction worker Lee Tate said in Jackson, Miss., where the mercury hit the mid 90s before noon Monday.

Fans pumped cool air Monday at the Vanderburgh County fair grounds in Evansville, Ind., but it was directed at the livestock, from rabbits and ducks to llamas and pigs. In Ohio, dog owners cooled pets with ice packs at a county fair competition.