With the Philadelphia region in the sweaty grip of a heat wave, air conditioners have been running non-stop. That could lead to sticker shock when the electric bills some in. Here are some tip for tying to keep the cost under control from the power companies NRG and PSEG.

• Set your thermostat four degrees higher when you're away from home for more than four hours.

• Try to keep your thermostat at 78 degrees. Each degree cooler could increase usage by up to five percent.

• Close your blinds or curtains during the day. Sunlight can increase the demand on your air conditioner by as much as 30 percent.

• Be sure your A/C fan is set to "auto" rather than the "on" position.

• Check air filters monthly and replace as necessary. A clean air filter keeps your A/C running at peak condition.

• Use fans to circulate air. They use less electricity than an air conditioner and can make it feel cooler.

• Don't cool unused rooms. Close the vents and shut the door to the room.

• Delay heat-producing tasks, such as running the dishwasher, until later in the day and wait until the load is full.

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