Children enjoy the cool water on a hot summer day at Crown Fountain in Chicago's Millennium Park on Wednesday, June 27, 2012. Temperatures in Illinois are forecast to top 100 degrees by Thursday, and authorities are urging the public to be cautious.
Swimmers try and keep cool in near 100 degree temperatures at Red Oaks Waterpark in Madison Heights, Mich., Thursday, June 28, 2012.
Swimmers try and keep cool in near 100 degree temperatures on a lazy river at Red Oaks Waterpark in Madison Heights, Mich., Thursday, June 28, 2012.
Jason Gerald, left, and Adam Hoffman jump into the Lake Michigan at Montrose Beach Thursday, June 28, 2012 in Chicago. The National Weather Service said the temperature Thursday hit 98 degrees. The last time it hit 100 was 2005.
Dennis and Shelley MacKay give their grandson Jacob, 2, a ride on a boogie board in York Beach, Maine, June 21, 2012.
Tourist Claire Jomeau of Paris, France, takes a break from sightseeing and rests on a bench in City Hall park during extremely hot weather on the first day of summer in New York, June 21, 2012.
Laborer Tom Paterick, 28, takes a water break during construction work on Mulberry Street in downtown Scranton, Pa., June 20, 2012.
Josh Cofield, 8, from Harrisonburg, Va., runs his tube through a stream in Riven Rock Park during a field trip for Brian Mayes Karate Summer Camp, June 21, 2012.
Bikram yoga demonstrators take a water break in New York's Times Square, June 20, 2012.
A runner takes a break along the Hudson River in Manhattan's Westside Park, June 21, 2012, in New York City.
Isaiah Daniels, 6, reacts as his mother Ingrid Daniels splashes water on him while in a pool at the John F. Kennedy Aquatic Center, June 20, 2012, in Newark, N.J.
A security guard yawns as tourists exit the 9/11 Memorial site during extremely hot weather on the first day of summer, in New York, June 21, 2012. Temperatures rose into the high 90s and broke records for the date in some city locations.
Water is poured over Andrey Krivetc, 11, while he is buried in the sand at Brighton Beach in Brooklyn, N.Y., June 21, 2012.
A sunbather does a cartwheel in Manhattan's Westside Park, June 21, 2012, in New York City. City residents enjoyed - or endured - a second day of the summer's first heat wave, with temperatures reaching the mid 90s.
Beach-goers play in the surf in York Beach, Maine, June 21, 2012.
People escape the heat in the waters of the Potomac River near Fairview Beach in King George, Va., June 21, 2012.
A group of teenagers swim in an abandon coal stripping pit known by locals as "the caves," in Coal Township, Pa., June 20, 2012. The pit is filled with runoff water, making it a popular swimming spot.
Michaela Blankenship, 9, jumps into a pool in her family's front yard as she tries to beat the heat wave in Baltimore, Md., on June 20, 2012. Also pictured are neighbors Dylan Vaden, from left, Devin Vaden and Jon Morris.
Eric Avila, 13, is cooled off by his sister Paige Avila, 11, as they find relief from the 95 degree weather that swept over the region on June 21, 2012, at the Riverside Park sprinklers in New Bedford, Mass.
John Law, 10, finishes applying sunscreen before heading into the sun during summer camp on June 20, 2012, in Fredericksburg, Va.
People enjoy the hot weather at the Brighton Beach section of Brooklyn in New York, June 21, 2012. In New York and Washington, D.C., temperatures reached 94 degrees before noon. Philadelphia was 93 degrees and climbing, and Boston hit 92 degrees. With the heat index added in, the air felt several degrees hotter.
Jakiyah Taylor, 3, runs through a splash pad at the Pennington Court Apartments on June 20, 2012, in Newark, N.J. Residents of the 223-unit public housing complex gathered in the court yard near the water sprinkler as temperature neared the 100-degree mark.
John Law, 10, plays in the water at summer camp in Fredericksburg, Va., June 20, 2012.
Sonya Kotler Heidenheim, 3, eats ice cream in Washington Square park, June 21, 2012, in New York City.
Errol Kaiser, 3, drinks ice water next to his mother, Liz Foster, during a visit to a fountain in Yards Park in Washington, June 21, 2012.
Three month old puppies Piper, top, and Emma frolic in the cool waters of Joe's Pond during a heat wave, June 21, 2012, in West Danville, Vt.
Construction worker Andrew Barbosa took a break from installing a curb on a street in New York to splash water on his face from an open hydrant, June 21, 2012.
People beat the heat as they play in the water at the Lower Falls of the Swift river, June 21, 2012, in Albany, N.H.
Dean Lo, right, along with his brother Jeremy and daughter Reynia Lo cool off in a water sprinkler located along the National Mall in Washington, June 21, 2012.
A sunbather lies out in Westside Park with a view of the Jersey City skyline, June 21, 2012, in New York City.