ABC7 AccuWeather meteorologists said highs would again reach into the mid-90s, with a heat index of 100-103 degrees.
After days of oppressive heat across the Chicago area, air quality is becoming an increasing concern as smoke from Canadian wildfires moves closer to the region.
Chicago appeared hazy Wednesday as temperatures climbed into the 90s, sending many residents in search of relief from the heat. Some headed to cooling spots such as 31st Street Beach, while others took precautions before spending time outdoors.
The National Weather Service said an Air Quality Alert is in effect for the Chicago area due to elevated ozone levels. The NWS said smoke levels may increase Wednesday night into Thursday.
The NWS said the alert may be extended depending on if smoke from Canadian wildfires reach the area.
Dr. Juanita Mora of the American Lung Association warned that elevated ozone levels, combined with the heat, can pose health risks.
"That ozone becomes like a sunburn into the lungs, and when that occurs people can start wheezing, having coughing, having respiratory problems, along from the heat, and all the dehydration that can occur," Mora said.
The Chicago Office of Emergency Management and Communications is encouraging residents to be prepared for extreme heat.
Cooling centers are expected to be open.
When the temperatures climb to extreme levels, it is important to check on relatives, neighbors, seniors and vulnerable populations. Chicago residents can call 311 for well-being checks.
The Chicago Park District said it may move activities indoors on Thursday due to the air quality.
"Chicago Park District programs may be moved indoors, have limited time outdoors, or be canceled," an update read in part. "The Chicago Park District reminds visitors to take precautions while enjoying our parks, beaches, pools, and facilities during these conditions."
The area remains under an Air Quality Alert due to elevated ozone levels and the threat of smoke from Canadian wildfires approaching the region.
Gabrielle Gedo, who was visiting from Washington, D.C., said she was taking extra steps to stay safe.
"Just hydrating a lot. And when, you know, with the wildfires, like having a mask on me, it's been useful," Gedo said.
Despite the heat and air quality concerns, many people continued to take part in outdoor activities throughout the city.
At Calumet Park, Chicago SummerDance in the Parks drew residents for salsa dancing and live music.
"SummerDance is like my favorite thing that Chicago puts on, so I want everyone to go see it. And the weather could be worse, but it's. It's very hot," said Elizabeth Davisson of Hyde Park.
Gedo also said she focused on enjoying the event despite the conditions.
"Just try focus on getting the moves right instead of, like, how much I'm sweating," she said.
The Air Quality Alert remains in effect through Thursday. Forecasters predict wildfire smoke could linger near the lakefront and across the Chicago area, creating additional concerns for people with respiratory conditions.
Brian Urbaszewski of the Respiratory Health Association said air quality has already reached unhealthy levels for some residents.
"We've reached into the unhealthy for sensitive groups, so the orange category for unhealthy air. And yesterday we reached the red category because of ozone smog. Ozone smog is a gas that's reactive that actually essentially burns the insides of your lungs," Urbaszewski said.
Health experts say children, older adults and people with respiratory illnesses are among those most vulnerable to poor air quality and should consider limiting time outdoors when conditions worsen.
At North Avenue Beach, Sam Shapiro and his dog, Badger, got in the water and out of the heat to stay cool.
"You know, he goes to the lake in the morning and the rest of the day he's either inside or would you like a little baby pool on the deck or something," Shapiro said. "It's a pretty indoor day for this guy."
Diehard runners took to the lakefront early hoping to escape some of the promised high temps and humidity.
Stuart Fisher is training for an October marathon and says he's been drinking lots of water and taking short breaks to cope with Wednesday morning's heat during his run.
"I checked the weather and saw that by 11, 12. It's already gonna be in the 90s and then you can buy that with humidity and you can go out but I think even the most season athlete whatever nutrition you have, planning, it's still gonna be hot and it's gonna be very challenging," Fisher said.
The afternoon heat is one reason why Stephanie Villa and her family traveled from the suburbs to celebrate her birthday by watching the sunrise.
"I really wanted to beat the like peak sun so we're gonna hit the beach and we'll do all the fun things before everyone's out here and it's super hot. Hopefully we'll be done by then," Villa said.
People may start to notice a haze across Chicago's skyline as toxic smoke from WILDFIRES in Canada settle over the area.
The conditions aren't stopping the volunteers with the clean-up, give-back initiative during their annual clean-up of the shoreline.
And it's certainly hasn't deterred music lovers from lining up outside of Wrigley Field, hoping to get tickets for Wednesday's Noah Kahan show.
The hot and humid weather has triggered an air quality alert for nearly all of the Chicago area.
Dr. Justin Fiala, a pulmonologist with the Northwestern Medicine Canning Thoracic Institute says because of high levels of ozone pollution, people with respiratory issues or ailments probably should stay inside.
"So for people with asthma or COPD, they can end up with kind of an acute attack because of those things," Dr. Fiala said. "Other people with other underlying conditions, say heart disease for instance, might feel like they are less able to do the things they normally able to do."
The stretch of intense heat and humidity drove many people indoors Wednesday, while concerns mounted over worsening air quality tied to wildfire smoke and elevated ozone levels across the southern Lake Michigan region.
At Chicago's Museum Campus, visitors sought relief from the heat in air-conditioned attractions.
"If you can be inside, be inside. It is so hot outside. We tried to stay indoors, stay cool. The Shedd was nice," said Kaylah Parks, who was visiting Shedd Aquarium.
The Museum Campus remained busy as many people tried to escape the hottest temperatures of the year by staying indoors. Others, however, chose to spend time outside despite the conditions.
"We have the beach, right? That was our plan: eat and then pack it all up, and then go cool off in the beach," said Paola Salgado, who was visiting the lakefront.
While Lake Michigan offered some relief from the heat, health experts warned about deteriorating air quality. An air quality alert is in effect through Thursday night because of wildfire smoke and elevated ozone levels.
"It'll affect everybody, and it's going to affect people over a large period, a large area ... the entire actually Southern Lake Michigan area is going to get blanketed with this really nasty smoke from Canada," said Brian Urbaszewski of the Respiratory Health Association.
Urbaszewski said the smoke contains tiny particles that can pose health risks.
"They're so small they can get from your lungs into your bloodstream and circulate throughout your body. They can irritate the lungs and cause breathing problems," he said.
The hazy conditions were already affecting areas farther north. A low-visibility warning was issued for drivers near the Mackinac Bridge, where smoke had reduced visibility.
Dylan Pearce, who recently completed the Mishigami, an 1,100-mile bicycle race around Lake Michigan, said he noticed the haze on his return to Chicago and worried about competitors still riding in northern Michigan.
"Definitely something I noticed driving back into Chicago this morning - was the smog on the skyline, and all I could think about was those poor guys out there today and what they got to deal with," Pearce said.
People with pre-existing respiratory conditions said they were already feeling the effects of the air quality issues.
"I have asthma too, so it feels a little bit heavier to breathe. Or like certain days that I've been outside for a little bit longer, I will find myself the next day having to use my inhaler," Salgado said.
"It's been a little hard to catch my breath or get like good deep breaths in. I get tired easier," said Jocelyn Cruz, who was visiting the lakefront.
Wildfire smoke was projected to reach the Chicago area overnight and continue into Thursday. The air quality alert remains in effect through at least Thursday night, and experts said smoky conditions could linger for several days.