Power outage checklist: what to do before, during and after

What a power outage can disrupt

A power outage is when the electrical power goes out unexpectedly. Ready.gov says an outage may disrupt communications, water and transportation. It can also close grocery stores, gas stations, ATMs and banks, cause food spoilage and water contamination, and prevent the use of medical devices.

Ready.gov also notes that extended outages may affect a whole community. The steps below work the same way whether the lights are off for an hour or for several days. Do the 'before' steps once, and you will be ready for all of it.

Before: list what runs on electricity

Start with an inventory. Ready.gov suggests you list the items you need that rely on electricity, then plan for batteries or other power sources, such as a portable charger or power bank. Think about phones, medical equipment, lights and anything else your household would struggle without.

Keep a flashlight for every household member, and find out whether your home phone works when the power is out and how long its battery backup lasts. Keep extra batteries for radios and flashlights too. Ready.gov says the Emergency Alert System and NOAA Weather Radio also provide emergency alerts, so a battery-powered weather radio is worth having.

Ready.gov's winter guidance adds two reminders that apply to any outage: keep in mind each person's specific needs, including medication, and remember the needs of your pets. Add both to your list now, while it is quiet.

• A flashlight for every person, plus spare batteries
• A power bank or portable charger for phones
• A radio with spare batteries
• Appliance thermometers for the fridge and freezer
• A cooler, and water containers or gel packs in the freezer
• Enough nonperishable food and water
• Supplies for pets

Before: plan for medical devices and medicines

If anyone in your home uses a medical device that plugs in, or medicine that has to stay cold, make a plan before an outage. Ready.gov advises you to talk to your medical provider about a power outage plan for electrically powered devices and refrigerated medicines. Ask how long each medicine can be stored at higher temperatures, and get specific guidance for any medication that is critical for life.

CDC adds that some drugs need refrigeration to keep their strength, including many liquid drugs. Ask your provider what backup is suitable before you buy any portable power station for a medical device. If there is an emergency, call 911.

• Ask your provider for a plan for any powered medical device
• Ask about refrigerated medicines and how long they last at higher temperatures
• Get specific guidance for life-critical medication
• Write the plan down and keep it where everyone can find it

Before: alarms, and somewhere to go

Install carbon monoxide (CO) detectors with battery backup in central locations on every level of your home. Ready.gov describes CO as a colorless, odorless gas that can kill you, your family and pets. Battery backup matters because the alarm keeps working when the power is out. See our guide to carbon monoxide alarms for options.

Also decide where you would go if your home gets too hot or too cold. Ready.gov says to check with local officials about heating and cooling locations open near you, and to go to a community location with power if heat or cold is extreme.

During: protect food, appliances and people

Keep the refrigerator and freezer doors closed. Ready.gov says a refrigerator keeps food cold for about four hours and a full freezer keeps its temperature for about 48 hours. Use coolers with ice if you need to, and check temperatures with a thermometer. Our food safety guide explains what to keep and what to throw out.

Turn off or unplug appliances and electronics. Power may return with momentary surges or spikes that can cause damage.

For light, CDC recommends battery-powered flashlights and lanterns rather than candles, gas lanterns or torches, to lower the risk of fire. If you have to use candles, keep them away from anything that can catch fire, and always stay near lit candles. CDC also says to keep a fire extinguisher handy and make sure your family knows how to use it. Good flashlights and lanterns make this easy.

• Keep fridge and freezer doors shut
• Turn off or unplug appliances and electronics
• Use flashlights and lanterns, not candles
• Run generators, camp stoves and charcoal grills only outdoors, at least 20 feet from windows
• Keep a generator at least 20 feet from doors and vents too
• Never use a gas stovetop or oven to heat your home
• Never touch a fallen power line

During: heat and cold

In hot weather, know the signs of heat illness. CDC calls heat stroke the most serious heat illness. It says body temperature may rise to 106°F or higher within 10 to 15 minutes, and that heat stroke can cause death or permanent disability if emergency care is not given.

With no air conditioning, CDC says to contact your local health department or find an air-conditioned shelter in your area. Even a few hours at a shopping mall or public library can help, and so can cool showers or baths. CDC adds that you should not rely solely on fans, because when temperatures are really hot they won't prevent heat-related illness.

In cold weather, never heat your home with a gas stovetop or oven. CDC says hypothermia is a medical emergency, and that a temperature below 95°F means getting medical attention immediately. Our guide to staying warm without power covers safer options.

During: water, power lines and fuel

CDC says safe water for drinking, cooking and personal hygiene includes bottled, boiled or treated water, and that water purification systems may not be working fully when power goes out. Our guide to making water safe has the steps.

Never touch a fallen power line, and do not drive through standing water if downed power lines are in it. CDC also says not to try to siphon gasoline, because it can cause serious injury or illness. If you use a generator, read our generator safety guide first.

After: food, medicine and getting back to normal

When in doubt, throw it out. CDC says to throw out perishable food in your refrigerator (meat, fish, cut fruits and vegetables, eggs, milk and leftovers) after 4 hours without power or a cold source, and any food with an unusual odor, color or texture. If you have a thermometer, Ready.gov adds a second test: throw away any food that has been at 40 degrees or higher for two hours or more. Whichever rule you hit first, the food goes.

Medicine needs the same care. If the power was out for more than a day, Ready.gov says to discard any medication that should be refrigerated, unless the drug's label says otherwise, and to consult your doctor or pharmacist immediately for a new supply. CDC adds that if a life depends on a refrigerated drug that has been at room temperature, use it only until a new supply is available.

Once things are back to normal, refill what you used: batteries, water, ice packs and any medicines. Then fix whatever slowed you down this time, so the next outage is easier.

• Check the fridge thermometer reads 40°F or below
• Throw out fridge perishables after 4 hours without power or a cold source
• Throw out food held at 40°F or higher for two hours or more
• Throw out food with an unusual odor, color or texture
• Discard refrigerated medicine if the power was out more than a day, unless the label says otherwise
• Call your doctor or pharmacist about replacements