SUMMER TEMPERATURES are on the rise -- and your electric bill isn't far behind.

Cranking up the air conditioning may help you stay cool, but you can expect some chilling summer energy bills as a result. A homeowner in Arizona pays roughly $212 just to run one standard room air conditioner for 1,000 hours over the course of a summer (that's about 11 hours a day). For central air, they pay an estimated $484, according to the government's Energy Star program.

Thanks to rising prices for the raw materials used to produce electricity -- oil, coal and natural gas -- those estimates might actually be low, says Ronnie Kweller, a spokeswoman for the Alliance to Save Energy, a Washington, D.C.-based nonprofit that promotes energy efficiency. The group recently raised its projection for annual electricity costs to $2,350 from $2,200 per household. Heating and cooling the home account for half of that amount, or about $1,200 a year. "If you can cut even 10% from your bill, that's hundreds of dollars saved," says Kweller.