Jon McCullough, 48, of the 2300-block of W. Ainslie on the Northwest Side, died early Thursday morning.
McCullough's mother, Alta, says her son spent a lot of time outdoors, and she became concerned. She says she tried to get him to a hospital.
"It didn't need to happen," she said, "if he had been willing to go to the hospital when I thought that he needed to."
The other person confirmed to have died from the heat is Eugene Burns, 53, of Maywood.
Officials say that if you see anyone suffering from symptoms of heat stroke or heat exhaustion, you should call 911 immediately.
During the day Thursday, the fire department responded to the Museum Campus Thursday afternoon to assist two teenagers suffering from the heat. They are expected to be OK.
Temperatures peaked at just over 100 degrees in Chicago on Thursday. The scorching heat touched off a mid-afternoon storm, sending folks at the museum campus scrambling for cover.
"Extreme heat and humidity are more than an inconvenience, they are dangerous and in some cases can be deadly," Dr. Suzzette McKinney, Chicago Department of Health, said.
City workers were both calling and visiting the sick and elderly Friday as part of wellbeing checks to make sure they were OK. Though most CHA buildings have air conditioning, officials say since Monday they have conducted more than 32,000 wellbeing checks.
"We also have plenty of water onsite, where we're making sure that management and staff are providing residents with water," said Eric Garrett of the CHA.
"We are not out of the woods yet, there is light at the end of the tunnel, nothing prevents any one of us from doing a well being check on a neighbor or someone who may need some assistance," said Chicago Office of Emergency Management and Communications (OEMC) Director Gary Schenkel.
For 28 years, Lueretha Chambers been delivering food to seniors for Open Kitchens, a private organization contracted by the City of Chicago to help feed those in need. As she makes her rounds on Thursday, she'll check on seniors to make sure they're handling the heat.
"A lot of them do not have air-conditioning. Some of them are in the house with sweaters on. It is steaming in their houses. I have clients with houses that feel like saunas," Chambers said.
On Wednesday, Chambers said she found a man who had fallen in his garage and couldn't get up. He's OK.
"We helped him up and put him back in his chair. I told him he should not be sitting out in the garage," Chambers said.
The Chicago Department of Family and Support Services also conducts well-being checks. Between when the heat wave started at Thursday, staffers had gone out on 118 physical checks, made 1,500 calls to seniors, and placed 7,200 robo calls with a heat warning.
The city was to have all six neighborhood cooling centers open Thursday. They're also offering free rides to help people get to them.
Meanwhile, the Cook County Medical Examiner's Office was working Thursday morning to determine if heat played a role in five deaths, including that of 95-year-old Iona Kedrics, who was found dead Tuesday night in her South Side home.
"I thought her nieces and nephews were coming out to watch for her. I didn't know she was over there by herself," Claudette Rachal, Kedrics' neighbor, said.
Later Thursday, the ME's office said that the heat was responsible for two deaths.
Chicago Public Schools (CPS) Chief Executive Officer Jean-Claude Brizard has canceled all CPS summer school classes canceled for Friday.
It was slow going Thursday for crews on the Wacker Drive reconstruction project. By 11 a.m., the pavement was 111 degrees according to ABC 7's thermometer, which uses a laser to take readings.
"[The workers are] not as efficient with the breaks and everything, more water breaks, but you gotta do that... you don't want them passing out around here," said Dan Gross, a contractor for the Chicago Department of Transportation.
Even the beach was unbearable, with the sand at noon a sizzling 128 degrees. At an empty playground, the black rubberized swings were a blazing 147.
A skateboard park, forming a mini-heat island, was simply too hot for William Burke, 12.
"You're just getting a little bit of a wind gust, but it's like hot wind. It's like hot air blowing in your face," said Burke.
At midday, about 2,000 people at Shedd Aquarium were evacuated after half the building lost power. Officials say there was no danger to marine life as backup systems kicked in.
"In the original aquarium building, we had all hands on deck," said aquarium spokesperson Roger Germann. "It was very orderly, we just asked folks to leave and they did, refunding folks where need be, and giving them comeback vouchers."
The Shedd officials said the power outage was an in-house electrical issue and they were investigating whether it was heat-related. Power was back on by Thursday evening, and the aquarium will reopen Friday morning.
An excessive heat warning is in effect until 10 p.m. Friday, and the Illinois EPA declared Thursday an Air Pollution Action Day.