It’s feeling like 100 degrees outside. So how cold should you set your A/C thermostat?

Energy costs are on our minds.

Whew, it’s hot outside. But how cold should you keep it inside?

Dealing with the 90s across Florida, with feels-like temperatures of more than 100, is never fun. Unless we work outside, many of us just like to stay inside — and to turn down the thermostat.

But Florida Power & Light suggests that you think before you lower your A/C temperature.

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Here’s what to know:

Recommended thermostat setting

While it’s not quite summer yet, it’s feeling like summer. So, here is some summer advice from FPL:

The utility recommends a setting of 78 degrees when you’re home, even though it’s a sauna outside, and 82 degrees when you’re not home.

“Summer heat is tough on air conditioning units,” FPL says,”but cooling your home doesn’t have to break the bank. Keep your energy costs under control.”

The utility says A/C can total more than 60% of a customer’s monthly electricity bill so this setting is the most efficient given the heat outside.

TECO Energy, which serves the Tampa area, also suggests setting your air conditioner’s thermostat at 78.

“This weather is not easy on our customers,” President and Chief Executive Archie Collins said. “Air conditioners are working harder, and bills are higher as a result.”

Saving money on cooling costs

The recommendations are based on efficiency, cost and strain on an A/C system. Utilities do their own research, but also have followed the recommendations of a federal program run by the U.S. Environmental Protection Agency and the U.S. Department of Energy, which recommends that thermostats should be set at 78 degrees for comfort and savings.

“When it’s really hot outside, your AC feels it too. Your AC is turning on a lot more now when it’s hotter than ever outside than it was perhaps in January, February, March, when it’s a lot cooler,” FPL spokesperson Bianca Soriano told WUSF Public Media last year.

Every degree set higher than the recommended range can save you about 5% on cooling costs.

Customers can also request a meter check and obtain a new “smart meter” if one is not already in place.

Another way to keep tabs is to download FPL’s free Energy Manager tool. The app lets customers track their home’s energy use to see which appliances are drawing the most energy, analyzes energy use so you can make modifications to perhaps use less but get the same efficiency and a lower bill, and get more tips in real time.

There’s also an FPL Mobile App on the Apple App store, Google Play or by texting “App” to MyFPL (69375) that can help keep you up to speed with your energy usage and reach someone from the utility.

Advice on how to keep it cool inside

In addition to the thermostat setting, FPL also has other advice on keeping your home cool:

Close the shades.

Don’t use the oven.

Clean or replace your A/C filter.

Consider buying a new high-efficiency air conditioner.