INDIANAPOLIS — When Katie Heddleston took her three boys to an Indianapolis playground Tuesday, she noticed the sun was gone.
"It is weird not seeing the sun. At first, you think it's foggy, but then you look at your phone and you're like this is still the stuff from the north," Heddleston said.
That "stuff" was a layer of haze covering central Indiana — a result of the plume from more than 400 Canadian wildfires moving south.
It's considered the worst wildfire season in Canada's recorded history and is impacting cities across the Midwest.
"My eyes are itchy. That's why I kept my glasses on just to help any particulates, but my eyes feel it the most," Heddleston said.
One of her sons wore a mask to help him breathe better at the park.
Experts are now raising concerns over unhealthy air quality.
Indianapolis leaders declared the next two days "Knozone Action Days," meaning the air we breathe is considered unhealthy.
"This particulate matter irritates mainly our airways, and it can be absorbed deep down into our lungs, causing pretty significant health damage," said Gabe Filippelli, with the Indiana University Environmental Resilience Institute.
Filippelli also felt the impacts of the haze.
"I've got a little bit of a headache today, and a headache is often because of problems with particulate matter," Filippelli said.
A normal air quality should be 0-50. According to one air quality map, parts of Indianapolis showed air quality readings as high as 170.
Particulate matter in air is measured using sensors.
"These sensors are all on people's front porches," Filippelli said.
This isn't the first time central Indiana has been impacted by the wildfires.
"This is the second set of bad days we've had from Canadian wildfires, and they're made worse by climate change, which tends to dry out the litter, causing fires to get much more intense and spread much more rapidly and extensively," Filippelli said.
Climate change is also believed to have had an impact.
"You can see it ramping up over the last couple decades, which is consistent with temperatures going up in a lot of these places, and drought-like conditions tend to increase in these kinds of environments," Filippelli said. "It's exactly like what a climate change future might look like more often than not."
Experts encourage people to limit outdoor exposure when air quality is poor.
"Very, very hazy. Even just looking out with the trees, you can see, it is not clear at all," said Jasmine Tracy, at JKT Fitness.
Most of Tracy's weekly cardio core class is indoors, but not all of it.
"I was kind of worried about it, because usually, we start out with a run, so how that would impact others who maybe don't work out as much outside," Tracy said. "Just being cautious of that and making sure people have their water or are taking their breaks when needed."
After a few days, joggers are feeling the poor air quality take its toll on their breathing.
Across town at the Benjamin Harrison YMCA, the smoky skies are keeping kids indoors. Time spent outside is being limited to 30 to 45 minutes.
"We want to make sure kids are still getting the camp experience, but we're able to move our STEM, our arts and crafts, and some group games inside," said Drew Kelley, youth and family director with the Benjamin Harrison YMCA.
Kelley said, normally, kids would spend all day outside. But with air quality so poor, he said safety has to come first.
"We have kids with asthma," Kelley said. "When they have asthma, we keep inhalers, we're authorized to help them with those inhalers, but we keep them with their counselors right there so that it is always there. And we've really had to pay attention to that with these air quality days."