Some residents stayed cool with icy drinks while others took a dip in the cool water of Lake Michigan. The beach at 63rd Street was a popular destination for many Chicagoans.
ABC7 spoke to some construction workers at a North Side high-rise who dealt with the heat with water and ice packs.
"We just work together, think it through beforehand, and drink a lot of water," said Marty Storck, construction worker.
The Office of Emergency Management urged people to seek shelter at cooling centers, especially the elderly.
At the Blue Island Salvation Army's cooling and recreational center, seniors escaped the heat and caught up with friends over lunch. Catherine Burnett told ABC7 she meets her friends daily at the center.
"The heat doesn't really bother me. And I do my own yardwork, and I just think positive all the time," Burnett said.
"I came all the way from Palos Hills to come and join the rest of the crew," said Lee Jordan.
"I come here for the camaraderie and friendship. It is cool here. But I'm managing to keep cool at home as well," said Bill Cosgrove.
Ruth Rickoff, 96, said she doesn't mind the hot weather.
"I'm used to having something on my arm, but it's really comfortable in here," Rickoff said.
"At this point in time, a cool place for them to be for the day and also to have their lunch with their buddies," said Jeannie Ferguson of the Salvation Army.
The elderly aren't the only ones who should worry about overheating. Young people should take precautions as well. Many youngsters visited the Salvation Army and community centers to play basketball and to stay cool.
"I come here to play basketball every day and join everybody, you know," said Tyshawn Hicks.
"This is a great place to stay cool. It's air-conditioned, it is safe. It keeps me out of trouble," said Malcom Lawson.
There are four cooling centers in Blue Island. The Salvation Army's cooling center is open from 9 a.m. to 9 p.m. For a complete list of cooling centers call 311.
ABC7 meteorologist Mike Caplan said Tuesday was the hottest day in Chicago since August 2, 2006.
Heat complicates firefighters' job
The heat is more than just uncomfortable. It's making conditions especially dangerous for firefighters and other people who have to work in it.
Firefighters doused flames at a West Side garage Tuesday. All their heavy gear combined with the heat takes its toll on the first responders. As a precaution, firefighters respond with extra personnel and drink lots of fluids. Doctors say that is important for everyone in extreme heat.
Meanwhile, other Chicago-area residents like Eisha Cooley checked up on elderly neighbors.
"We try to look after the elderly. It's been hot a couple days. We make a wellness check to make sure they got enough water," said Cooley.
Down the street, some residents cooled off with a water fight.
"When you can't get everybody in the family to the beach, it's time to take the hose out and just wet everybody that goes past," said Vonda Page.
Yolanda Thomas did a brisk business selling snowballs from her stand in Roseland.
"Perfect day to have snowballs. I'm selling out. All my juices, it's practically gone," said Thomas.
The soaring temperatures were enough to prompt some Northwest Indiana school officials to let kids out early. And in Chicago the heat caused switching problems on a couple Metra rail lines which led to delays.
The high temperatures failed to discourage people from outdoor activities like running. But experts urged caution.
"Hydration is key at this time of the year. Taking in fluid is so critical," said Dave Zimmer, Fleet Feet Sports.
Tips to stay cool