Local authorities say they've seen several blow-outs this week because of the triple digit temperatures.
A frightening tire blow-out left Linda Myers and her sister stuck under the scorching sun along Highway 140 near Catheys Valley.
"It's just hot, it's just baking, everything's baking, and we came around a curve and all of the sudden, pow! It's like it just came right off the rim," Myers said.
Fortunately a friendly driver found a repairman for the sisters, who helped get them back on their way to San Francisco. But the Highway Patrol says blown tires can cause dangerous, and even deadly, crashes.
"It does have the potential to cause very serious accidents, especially if you brake after a tire blowout because you can easily lose control of the vehicle," Officer Obed Macias said.
The owner of Tire World in Merced says he's seeing a spike in blow-outs because of the triple digit temperatures. The hotter a tire gets, the higher the risk of failure.
"You have tire monitors in cars, but by the time they come on it's too late," Dave Nannini said.
Nannini says that's why it's critical to check your tire pressure before heading out in the heat.
"90% of the cars have a little dash plaque that's right here on the car that tells you the tires must maintain 33 pounds or 35 pounds. That's the most common air pressure for a typical car," Nannini said.
Once you know the right number, you can use a simple air gauge to check the tire.
"This tire's got 35 pounds," Nannini said.
Or many tire shops will check it for free.
"For our business here, we always do it for free, people come up, I want to check their pressure, I want them safe," Nannini said.
If you do have a blow-out, authorities say gradually slow down and pull over to the right shoulder of the road.
"Braking is the worst thing you can do when you get a tire blow-out because you can lose control of the vehicle," Macias said.