Heat wave strikes and you think of last summer's dreadful utility bills, and all those coal-burning plants powering air conditioners and spewing global-warming carbon dioxide. Air conditioning represents 22 percent of an average household's total energy bill, according to the Rocky Mountain Institute. Aside from running out and buying that new Energy Star air conditioner, here are five quick ways to cool down while minimizing energy use and carbon emissions.

1. Keep your air conditioner thermostat as high as you can with comfort. Every degree you adjust it upward saves 3 percent in energy costs, according to the Union for Concerned Scientists (UCS). Make sure your air conditioner is on "recirculate," which won't pull in outdoor air.

2. Use a ceiling fan or other fan when you can; they eat far less energy that air conditioners. A table fan can direct cooler air from the shady side of your home to the sunny side, and also provide a welcome kitchen breeze on sultry nights. Consider installing an Energy Star certified ceiling fan, which uses 20 percent less energy than a standard ceiling model.

3. Whenever it's cool and fresh outside, say, after a thundershower, crack your windows an inch or two to create a draft that will refresh indoor air.

4. Apply low-cost, low-E films to window glass, which can save you up to 15 percent on electricity bills. Companies to consider include Snap Tint or Solar Gard.

5. Close blinds and curtains in peak sunlight hours. Light-colored window treatments can reduce heat indoors by 50 percent. For non-PVC blinds and shades, which won't leach toxic phthalates into your air, check out Earth Shade, or special solar shades by Hunter Douglas.

For more cool green tips, visit ACEEE, Rocky Mountain Institute and UCS.

This article originally appeared in Plenty in June 2008. The story was moved to MNN.com.