Hail was spotted in Elgin and more storms are in the forecast.
A heat advisory kicked in at noon and remained in effect until 8 p.m. Officials encouraged people to take precautions, especially when outside. Tips for keeping cool, safe in the summer
City of Chicago's Cooling Centers (PDF)
The 100-degree day was downright dangerous for some.
Fire and heat proved to be a brutal combination for Chicago firefighters in Little Village Thursday night. The heat was so severe one firefighter had to be treated for heat-related problems. Nearby, other crews hopped into a supply truck filled water jugs, and hoisted them onto their shoulders, headed for the troops. No one suffered serious injuries.
The heat also resulted in tragedy. Lake County authorities say a 62-year-old boater jumped into a lake near Antioch to cool off. His 69-year-old friend tried to rescue him. Crews saved him, but the younger man is still missing.
"It is difficult for search and rescue crews simply because of the heat," said Sgt. Karen Kates, Lake County Sheriff's Office.
At Union Station, Metra trains were delayed because officials say the heat stresses the tracks and signals.
"It's very annoying, especially people, they're very crabby. They're pushing. It's just a mess. Chaotic," said Brittany Cummings, delayed commuter.
"Who knows when I'm going to get home," said Maria Manhart, another delayed commuter.
If it continues, the extreme heat may cause more problems.
"We usually see more coming in for heat-related illness as the heat wave rolls on. Not necessarily the first or second day," said Dr. John Williams, Emergency Medicine, University of Illinois Hospital.
The heat may just depend on your perspective.
"It's cool almost to me, I know that sounds funny right? I could put a sweater on right now. I really could," said Michelle Padilla, a tourist from Arizona.
To deal with the high temperatures, Commonwealth Edison said it has 300 extra crew members on duty to deal with power outages and some schools also have cancelled summer classes. Classes were scheduled to resume Friday.
Suburban residents seek refuge at public pools
Woodridge's Cypress Aquatic Park was packed to the gills Thursday with nearly 1,000 people seeking refuge as the poolside temp scraped 110 degrees.
Nilsa Ortiz-Jones described her game plan to ABC7.
"Stay in the water for as long as it's as hot as Hades out here," Ortiz-Jones said. "It's fantastic."
"This is the best place to be on a hot day," said Sharon Funk, Woodridge resident.
"I go to Canyon, Arizona, where it's 110-112 just like it is here. It's perfect. This is nothing to me. I enjoy this," said Rick Bogdan, Downers Grove resident.
Loyola's new Urgent Care facility in Burr Ridge was a cool and quiet place. Dr. Carolynn Zonia said these days most people know how to cope.
"We don't have the prolonged heat," said Dr. Zonia. "People seem to be smarter about getting out of the heat. We're checking on the elderly and getting people who need it to cooling centers."
There was no way to beat the heat for the kitchen staff at Smoke Daddy, where the cooker was set at 220 degrees and the ribs stay on for 14 hours.
"Trust me, people fill up. They eat this stuff 365 days a year!" said Carlo Carani, Smoke Daddy BBQ.
Extreme heat puts stress on air conditioning
"When I heard it was going be 100 degrees today, I said 'I'll never make it," said Rose Faciana, 91, of Hinsdale.
Faciana says her house is like an oven. The air conditioner stopped working Wednesday. The thermometer inside her home read 86 degrees on Thursday. She called for help.
"We're working 12-14 hours a day just to keep up with demand," said Andy Zemaitis, Four Seasons Heating & Air Conditioning.
Four Seasons techs will respond to 400-500 calls today: a 40-percent increase. He had some tips for what people should do.
"Annually get their air conditioning serviced. Change your filters monthly," said Zemaitis.
Rose Faciana and her grandson Alex are just starting to cool off. Their air conditioner is fixed.
"It's hot. I'm sweating," said Alex.