Heat exhaustion, heat stroke possible as cars heat up in the sun

Explainer: Why cars get so hot in the sun

Cars heat up very quickly when sitting in the sun. Even a relatively cool day by Texas standards can result in dangerously high temperatures inside your car.

AUSTIN, Texas - As temperatures heat up heading into summer, it's time for a reminder to never leave kids, pets, or people in cars.

Cars heat up very quickly when sitting in the sun. Even a relatively cool day by Texas standards can result in dangerously high temperatures inside your car.

According to the National Weather Service, temperatures in your car can exceed 100 degrees in less than 20 minutes when the outside temperature is only 80 degrees.

Temperatures this week will be much hotter than expected, highs will be 101-105 across Central Texas. That means parking lot temperatures will easily exceed 110 degrees because of the heat from the pavement. In your car, it could exceed 130 degrees in less than 10 minutes.

Heat exhaustion and heat stroke are possible within 15 minutes in 130-degree conditions and the warming won't stop there. If parked for around an hour, temperatures in your car will peak around 140 degrees with the dashboard approaching 160 degrees.

So what causes these crazy hot temperatures in your car? A couple of words: the green house effect.

Basically light energy from the sun can travel through glass, but heat can't. The light from the sun is absorbed by your seats, dashboard, or anything in your car. That warms the material which then warms the air. The heat energy then tries to escape but is trapped by the glass. More light heats your seats and the process turns your car into an oven.

Darker materials like black or dark gray cloth or leather are much more efficient radiators of heat energy. That's why if you have dark upholstery, your car feels so hot when you get in. Sun shades on your dashboard and properly tinted windows can help keep your car cooler. But the best way is to park in the shade.

Even if the car is parked in the shade it is extremely important to never leave kids, pets, or people in un-air-conditioned cars for any amount of time. A shaded car can be less hot than one in the sun, but temperatures can still exceed 110 degrees which can cause heat illness in about 30 minutes.