FRESNO, Calif. (KFSN) --The extreme heat is choking the Valley and creating air quality concerns.
On one of the hottest days of the year in Fresno, we found Rojelio Ruiz training for one of the toughest marathons in the world.
"It's hard to breathe," the runner said. "It's pretty hard so you just have to stay hydrated."
Triple digit heat, he says, is good because in two weeks he'll be running 135 miles through the Badwater Basin in Death Valley.
"some people would say you're crazy to be running in this heat," an Action News reporter asked.
"Yeah, it is true," Ruiz replied.
For the rest of us, it's not such a great idea.
Smog levels tend to rise with the temperature, and the air is stagnant and we are breathing it all in.
Rita Hicks can feel it.
"It was all nice and cool, then all of a sudden, you're in shock by this heat, like a heat wave," she said. "It can take a toll on your body."
It's also a concern at Fresno Unified.
Brett Mar, the athletic director, says when it hits 105 outside the classrooms students have to stay inside.
"It's for the safety of the kids," he explained. "Especially when it's forecast to be 106, 108 degrees, it's brutal."
Dr. A.M. Aminian agrees and he says it's especially tough for people with breathing problems or conditions like heart disease and diabetes, but even a healthy person can fall to the heat.
"Sweating more does not make you tougher, sweating more in this weather and breathing this air is going to be very damaging," he said.
As for Ruiz, he understands the risk and he says this is just another training day.
"It's like everything," he said. "Once your body gets used to it, you just don't feel it anymore."