Big changes in the weather can play games with your car's tires. Ron Wright, owner of Tire World, explains.

"Well, going from warm to cold typically will result in a lower tire pressure. That's why so many people wake up on these brisk, cold mornings and their tire lights are on," says Wright. "What happens is the air molecules shrink which reduces air pressure."

This can lead to a flat if you don't show some TLC.

"I feel you should check your tires, or at least look at them, every time you get to the car. Just a quick look, and that's that," adds Wright.

He suggests you check the pressure once a month. It's easy to do with inexpensive gauges available auto parts stores. It's important to keep the pressure at the level recommended by the manufacturer. This can be found in your owner's manual or the inside of the driver's door.

"When that's [air pressure] altered, the way the car can perform will also be altered. It may drive poorly," explains Wright.

If you need to feed your tires some air, where you go makes a difference. Wright says taking your car to a service center like his is more reliable than some do-it-yourself pumps at gas stations.

"You may not get anything for your quarters you put in, or you may get a lot of water if they're not maintaining or servicing their tanks properly," says Wright.

He also says using Nitrogen instead of plain old air keeps the pressure more stable because Nitrogen molecules are larger. They don't react as much to changes in temperature.

Even if you take precautions you still might run over something and get an flat. Wright says only change your tire if you're on level ground and you know what you're doing.

"Probably the best safety tip is to know whether you feel you can or cannot do it, " adds Wright. "Sometimes they're easy, sometimes they're not."

Wright says he has customers of all ages who don't know how to change a tire, or need a refresher course, like Nancy Harrison.

"My dad made sure all of his kids knew how to change a tire," says  Harrison. "But if I ever have to change a tire--it's been a long time--I no longer remember. I sure I hope I never have to do it."

For tips on safely changing a flat tire, visit the Department of Motor Vehicles website.