High temperatures have not only made the air quality worse, but it's also prompting people to take extra precautions, especially when they're outside.
The Fresno City College football team is used to breaking a sweat. But, during this conditioning class Tuesday, when temperatures reached the triple digits, head coach Tony Caviglia reminded players to rest often, and take frequent water breaks.
Fred Gaines said, "He told us from the start, you know we were going to go up against the weather, but we gotta put in the work."
At Fresno State, a group of kids took part in an indoor cheerleading class. It's part of the university's summer camp program, which caters to nearly 600 children. Normally, most campers would be outside. Instead, counselors were instructed to move some classes indoors, and make sure each child stayed hydrated.
Sergio Verduzco said, "We encourage water breaks throughout the entire day. We scatter around campus igloos with water so they can refill their water bottles."
Cal Fire officials say without enough water and rest, people can experience serious heat related injuries.
Tuesday, a farm worker in Reedley was taken to the hospital for heat exhaustion.
As for firefighters, they're required to follow the department's hydration policy.
John Dominguez said, "We try and either request an additional response because of the heat wave and also we give them longer rest periods."
The San Joaquin Valley Air Pollution Control District is also stepping up its heat response. Officials say when it's this hot, air quality deteriorates throughout the day, because pollutants like auto exhaust bake in the heat.
Jaime Holt said, "We are anticipating that ozone levels are gonna get pretty high and air quality is going to get pretty bad going into the next few days as we continue to see these triple digit temperatures."
The Air Quality Control District is urging people to reduce your driving over the next few days.
They're also advising people with health problems, like asthma and emphysema to stay inside if you can.