Keeping your cool in your oh-so-hot car this summer

On a hot summer day, the temperature inside your car can climb more than 40 degrees in an hour and reach dangerous highs. Here are some ways to cool things down, from ordinary air conditioning to more high-tech solutions such as cooled seats and U.V.-reflecting window film.

1. Window film:

Solar Gard makes a nearly colorless film that goes over your car's windows and can block up to 99 percent of ultraviolet rays and 66 percent of heat-causing infrared rays. The company says its film keeps the car's interior around 10 degrees cooler. It costs around $180 to $240 per car for a Solar Gard dealer to install. Darker versions cool the car down even more, but be careful, states have differing tint laws that determine how dark a car's windows can be.

2. Solar-powered auto fans:

There are several small, solar-powered vents on the market that suck hot air out of your car and blow cool air in while it's parked. They connect to your window and don't require batteries. Eco Solutions makes one with recycled plastic that sells for $28.

3. Cooled seats:

Most luxury brands such as Cadillac, BMW, Mercedes-Benz, Infiniti and Lexus offer cooled seats. The seats blow hot air away from your body and force cooler air into the seat. You can also buy cooling seat cushions with adjustable fan speeds that plug into your car's outlet. Smarthome.com, an online electronics retailer, sells one for $52. For children's car seats, there's the Baby Bee Cool cover, which cools a seat for up to 10 hours when you insert ice packs into its pockets. The pad is $44.95 at bargainsforbabies.com.

4. Window shades:

They've come a long way from the cardboard versions you used to cram into your front window. Top of the Line, which sells auto detailing supplies and gadgets, offers a retractable, accordian-fold sun shade that attaches to one side of your front window. You can pull it across the window when you're parked and tuck it away when you're driving. It's $35.95.

5. Air conditioning.

Air conditioning is a good solution, but it's not free. It can reduce your vehicle's fuel efficiency by up to 10 percent, according to personal finance site Bankrate.com. If you're going 40 mph or less, consider rolling down the windows if you want to save fuel. At highway speeds, however, turn on the AC and close your windows. Open windows create drag on the vehicle that can reduce fuel efficiency by 20 percent or more if you're going 55 mph.