Here’s what to know about the heat.

Starting Tuesday, cooling centers — indoor, air-conditioned spaces for public use — will be open during the day in New York. The city’s fire department is also turning some fire hydrants into water sprinklers. If you’re staying at home, here’s what you can do to stay as cool as possible indoors, whether you have an AC or not.

What’s the ideal temperature for your home?

While you should do what feels most comfortable for you, Carrier, an air-conditioner manufacturer, suggests on its website that 72 degrees is the generally accepted “comfortable indoor temperature for many people.” It continues, “It strikes a good balance between comfort and energy efficiency, making it a popular choice for residential settings.”

If you’re away from your home, set your thermostat for higher than usual to save energy and to prevent your AC unit from potentially busting. At night, because heat can disrupt sleep, 60 to 67 degrees is recommended by the Cleveland Clinic.

How do you keep your furry friends safe?

It depends on the animal, and its size and type, but pets are generally less tolerant of higher temperatures than humans.

Dogs, the most common pet in the country, tend to overheat when the temperature is between 81 and 85 degrees, according to the American Kennel Club. “An ideal temperature doesn’t exist for all dogs, since their normal body temperature will vary according to size,” the organization states on its website. It also suggests installing a temperature alarm that can notify your phone if your AC fails and you’re not at home to notice.

How do you maintain your AC?

If your AC is broken, it might be too late to find a repairman to fix it in time for the heat wave, but going forward, experts recommend servicing your AC unit once a year. A technician will typically check for and diagnose issues with the system, clean it and change out the filter.

Depending on your unit, you may be able to change your filter yourself. Carrier suggests inspecting your filter every two to three months, and certain factors might affect how often you’ll need to change it. (For example, if you have a pet, you may need to replace the filter more frequently because of its shedding.) You can look for an online guide on how to change the filter — whether it is for a window unit, floor-mounted or other. Just make sure to turn your system off first.

What can you do if you don’t have an AC?

You can close your blinds or cover your windows to minimize your exposure to direct sunlight. Stick-on solar film, which can be bought online or at home-improvement stores, is also an option. This can deflect infrared heat that would otherwise come in through your windows.

While fans don’t cool the air, the breeze they create can have a cooling effect. Wirecutter has a guide to room fans in varying sizes. Make sure your ceiling fans are running counterclockwise, so that air is pushed downward.

If you’re able to obtain it in time, Wirecutter also suggests this portable AC.

What are some things to avoid indoors?

Steer clear of using appliances that generate heat, such as an oven, clothes dryer, iron or blow dryer. New York Times Cooking has a list of “No-Cook Recipes for a Heat Wave” so you can prep a meal without turning on your stove top.

Try to avoid dark fabrics for curtains, upholstery or clothing, as they can absorb heat more easily. You can also turn off lights — having too many on close together can heat the surrounding air.

Avoid thick covers and blankets. Percale sheets tend to be more breathable, and Wirecutter has a guide for bedsheets for hot sleepers.

Can I report my landlord if my apartment is unreasonably hot?

While some cities, like Dallas, have air-conditioning requirements for rental apartments, New York City does not. (Landlords in New York are legally obligated to provide heat and hot water.) But if you live in an apartment that had an AC when you moved in, landlords are responsible for maintaining it and replacing it if it’s broken.

If they refuse to fix it or are unresponsive, you have options. Ronda Kaysen, a real estate reporter and former “Ask Real Estate” columnist, suggests paying to replace the AC unit yourself if you can then negotiate your rent, asking for the same amount for the upcoming year. You could also take your landlord to court, but that could be more time-consuming and expensive than paying to fix it yourself.