Millions of people in 20 states are under air quality alerts as smoke from Canadian wildfires is again moving across the U.S.

Hundreds of wildfires burning out of control are creating hazy, smoky conditions from the Northeast to Alabama to the Great Lakes. Pennsylvania officials declared a code red Wednesday as smoke covered Pittsburgh.

It’s a similar situation in Detroit which is experiencing some of the worst air quality in the country.

“It’s like you’re just sitting at a campfire all day if you’re outside,” said Darren Riley, JustAir CEO. 

In Chicago, the EPA labeled the air “unhealthy” and warned older people and those with respiratory conditions to stay inside.

“I mean, I run a hundred miles a week, so this is going to be dangerous today,” said Chicago resident Priti Marwah.

Meanwhile, a dangerous heat wave is baking Texas and moving eastward. The scorching heat is blamed for at least 13 deaths in the Lone Star State. 

Texas officials are asking people to curb their power usage, but so far, the grid is holding up under high demand. In Dallas, officials are opening up cooling centers to help those coping with extreme temperatures.

“We know that this extreme heat can be dangerous, especially for seniors and our most vulnerable neighbors,” said one official.

Now the triple-digit temperatures are spreading east to Mississippi and Tennessee.

The heat and smoke have many cities reconsidering the annual Fourth of July fireworks displays to reduce the risks of fires.