Officials say with the heat index it could feel like 105-degrees outside. The last time the heat index got that high was August 2006.
But Thursday is expected to be the most oppressive day, according to ABC7 Meteorologist Jerry Taft. "We do expect to see some heat advisories and maybe even an excessive heat warning by the end of the week. So it's going to be hot," Taft said.
For the first time since Millennium Park opened, a sprinkler was added to help people cope with the heat as well as cooling bus for those attending the Downtown Sound concert series Monday evening.
"As the heat grows or it lasts longer, it's more cumulative so these measures are even more important than ever," said Matt Nielson, department commissioner at Millenium Park.
The thought of more heat and humidity is dreadful for many but not all.
"I'm from Texas so I love the heat actually. I feel like If you don't have at least few days of this, you feel like you didn't have a summer," said Shelley Stunard.
"As long as I'm somewhere where there is air conditioning, I'm OK," said James Porter.
As long as the air conditioning works, that is. Christy Glass couldn't wait for the Four Seasons repairman to come to fix her air conditioner. The company has been getting hundreds of calls this week.
"The other day when it got really hot, I went to turn it out and the fan was blowing just fine, but it was just re-circulating the same warm air, it wasn't cooling," said Glass.
"It looks like it's just low on Freon," said Randy Szymanek, Four Seasons Heating & Cooling.
Working without the luxury of air conditioning are firefighters. On Monday morning, many were called to battle a house fire on the Northwest Side.
"We rotate those people on a 10 to15 minute basis, make sure they come out, they go into a cool area that's called a rehab area where we have cool drinks," said Dep. Chief Thomas Lynch, Chicago Fire Department.
Stay hydrated and take breaks, says Dr. Linda Druelinger, an emergency room physician at the University of Chicago. If not, heat stroke is a real possibility.
"People may start to feel some cramping, they may start to feel a little bit nauseated. One of the thigns that we worry about in particular is atually a lack of sweating," said Dr. Druelinger.
Dr. Druelinger says if residents experience those symptoms they should go to the emergency room.
With the heat advisory comes warnings from officials to take precautions, such as limiting time outside, drinking lots of water and wearing loose-fitting clothing.
"I feel like taking another shower," said commuter Sharon Boye. "When I get to the office, I plan on going to the bathroom, just freshening myself back up again."
The City of Chicago's cooling centers are open at libraries, park districts and police stations. Residents can call 311 to find location. The water of Lake Michigan is also a popular cooling off place.
"It was so hot, I just came here and wanted to cool off in the lake. It's wonderful, perfect," Vada Seals, beachgoer, said.
Residents are encouraged to check on elderly neighbors. Small children and pets are also most a risk during hot weather.
The Chicago Department of Family and Support Services operates six cooling centers, open 9 a.m. to 5 p.m. Monday, Tuesday, Thursday and Friday; and 11 a.m. to 7 p.m. on Wednesday. Those locations:
845 W. 69th Street
Chicago, IL 60621
10 S. Kedzie Ave.
Chicago, IL 60612
4314 S. Cottage Grove
Chicago, IL 60653
4740 N. Sheridan Road
Chicago, IL 60640
8650 S. Commercial Ave.
Chicago, IL 60617
4357 W. Armitage Ave.
Chicago, IL 60639