2. Reduce indoor heat
Computers, lamps, curling irons, and dishwashers all can act like mini-space heaters. During the summer months, try to use as few of these heat-emitting appliances as possible.
Clean laundry and dishes in the evening, air-drying them whenever possible. Make sure bathroom and laundry-room fans vent hot air outside.
Avoid cooking with the oven – use the microwave or an outdoor grill instead. And avoid incandescent light bulbs. Incandescent bulbs convert up to 90 percent of the electricity they use into heat.
Turning off appliances will not only keep temperatures down but also costs. For example, turning off a home computer during the day can save about $75 in energy costs a year, according to the Energy Department.