For example, most of the Delaware Valley remains under a Code Orange air quality index.
Victoria Wenstrup, an environmental specialist with the New Jersey DEP, says that serves as a heads-up for people who fall into certain health categories.
"Our sensitive population like children, teens, and the elderly are at risk," she said. "So, people who also have pre-existing conditions and people in the sensitive groups should pay more attention to the air quality on those particular days."
Dr. Mark Goldstein, Chief of Allergy and Immunity at Pennsylvania Hospital, says it's important to remember that vulnerable population exposure to ozone and particulate pollution, even short-term exposure, can be dangerous.
"That could include hospitalization for asthma, COPD, even mortality in some cases," Goldstein said.
Isabella Bentivogli of Cherry Hill says as someone with asthma, she is a good example of someone who needs to play it safe.
"Getting off the subway and walking here," she says, "I felt very short of breath and had to definitely walk slower. So, when I realized that the air quality wouldn't be as good as normal, I definitely budget in more time if I'm walking somewhere, and I always carry my rescue inhaler with me."
As always, the advice remains the same under these conditions for the very young, the very old, and people with respiratory ailments.
It begins with avoiding outdoor activity as much as possible and remaining hydrated.
"Perhaps wearing a mask is also a good idea, the masks we've worn for COVID," Goldstein added. "These N-95 masks would be appropriate if you're spending time outside."
With the excessive heat, many have opted to stay indoors to keep cool, no matter whether they're in a sensitive group.
"It's unreasonably hot, you walk outside and feel like you're going to melt a little bit," noted John McGrady from Manayunk.
Restaurants say few people are seeking outdoor dining because of the skyrocketing temperatures.
"You can definitely tell how the overall heat is affecting everything," said Allie Ryan, the manager at Goat's Beard. "It's really not anybody's first choice."
While some businesses thrive on hot weather, restaurants with outdoor seating may not.
"We have 10 tables out here that just aren't being used at all, that stinks," Ryan noted.
One business thriving in the heat, however, is the Cheltenham Library System. Officials there say all branches are doubling as cooling centers for the public.
"We recognize that the thing that our community most needs during these heat waves is a cool place to be," said Elkins Park Head Librarian Elizabeth McGoran.
Many have hit the books to keep cool.
"This is a blessing. I don't think anybody thinks to go to the library," said Khadijah Bey from Cheltenham.
There are plenty of ways to keep track of the air quality conditions in your community.
That includes the EPA's Air Quality Index monitor.