With summer temperatures in full force, Arizona’s third-largest city is asking its residents to conserve energy.

The city does not own or operate any electric generators, according to a press release, and purchases its electric supply through various short and long-term agreements.

Supply costs have increased dramatically this year due to the region’s population growth as well as the transition to newer and cleaner energy production, according to the release.

“In the Southwest we are facing some of the hottest temperatures on record, which leads to increased demand on the utility systems and rising costs from our suppliers,” Mesa Vice Mayor Jenn Duff said in the release.

“Energy conservation not only lowers our utility costs, but it also creates a more healthy, sustainable environment for everyone. Even the smallest change can lead to lasting benefits for everyone.”

Residents are asked to set the thermostat at 78 degrees during the peak hours of 3 p.m. to 8 p.m. or when not home as setting the air conditioner five degrees higher could save up to 20% on cooling costs, according to the release.

Other recommendations include cooling the home with ceiling fans, closing windows and doors and cleaning or replacing filters as a dirty filter forces the air conditioner to work harder.

People can also conserve energy by turning off unnecessary lights and use desk lamps with LEDs instead of overhead lights, turn off computers when not in use, unplug phone chargers and power strips without a switch when not in use as well as postpone using heat-producing appliances like the oven, dishwasher, washing machine and dryer during peak hours.

Frank McRae, the city’s energy resources director, said in the release that Mesa is working to reduce peak electrical usage at city facilities while also developing programs for customers to save energy and money while reducing demand during peak hours.

Click here to read the full press release.