How to Get Through a Power Outage Safely at Home

Why this matters

Most power outages are an inconvenience: a few dark hours, a warm fridge, a reset clock. The injuries and losses come from what people do to fill the gap. A candle left burning, a generator running in the garage, a grill brought inside for heat, a fallen line someone walks up to, a fridge opened every half hour until the food spoils, a houseful of equipment slamming back on at once when the power returns. Getting through an outage well is mostly a matter of a few habits in the right order.

Before anything else: treat every fallen or low-hanging power line as live, whether or not it is sparking and whether or not your lights are out. Stay at least 30 ft away (some utilities say 35), keep children and pets back, do not touch anything the line is touching (a fence, a car, a puddle, a tree), and call the utility's outage or emergency line, or 911 if anyone is hurt or there is fire.

Step 1: Find out whether it is just your house

Look out the window. Are the neighbors' lights on? Are the streetlights out?

• The whole street is dark. It is a utility outage. Go to Step 2.
• Your house is dark but the neighbors have power. Look at your electrical panel, without touching anything if the floor is wet. If the main breaker or a group of breakers has tripped, see related: How to Reset a Tripped Breaker Once. If nothing in the panel has tripped, the problem may be on the utility's side of your meter, which is theirs to fix: report it.
• Some rooms work and others do not, or lights glow brighter or dimmer than normal, or flicker when a big appliance starts. This can mean the utility connection to your house has partly failed. It can damage electronics and appliances and is a fire risk. If you can reach the panel standing on a dry floor, switch the main breaker off, then call the utility's emergency line right away and say "half my house has power and the lights are brighter than normal." Leave the main off until the utility says the connection is repaired. Smell of burning or sparks anywhere: get out and call 911.

See related: Reading Your Electrical Panel and Its Breakers.

Step 2: Report it, even if you think others already have

Report the outage to the utility through its outage number, text line, app or website. Utilities build their picture of an outage from reports, and a quiet street can sit at the bottom of the list because everyone assumed a neighbor called. The report also usually gets you an estimated restoration time, which you need for Step 3.

If anyone in the house depends on powered medical equipment (oxygen, a CPAP, a home dialysis machine, medication that must stay cold), say so. Many utilities keep a medical-needs registration; it rarely gets your power back faster, but it can get you a call and information about cooling or warming centers. Set that up before you need it.

Step 3: Keep the fridge and freezer closed, and start a clock

Note the time the power went out and keep the refrigerator and freezer doors shut. The guidance from the U.S. Department of Agriculture's food safety service is that:

• a closed refrigerator keeps food safe for about 4 hours;
• a full closed freezer holds its temperature for about 48 hours, a half-full one for about 24 hours;
• refrigerated perishable food (meat, poultry, fish, milk, soft cheese, cooked leftovers, cut fruit) that has been above 40 F for more than 2 hours should be thrown out.

If the estimated outage is longer than 4 hours, move the things you cannot lose (medication, baby formula, milk for the children) into a cooler with ice or frozen packs before the fridge warms, so the fridge door opens once instead of all evening. An appliance thermometer in the fridge and one in the freezer turn guessing into a reading.

Step 4: Turn off and unplug what will surge back

Unplug computers, televisions, game consoles and chargers, and turn off the switches on big appliances that would restart on their own: window air conditioners, space heaters, the dishwasher, the washer and dryer. Set the thermostat to off. Leave one lamp switched on so you know the moment power comes back.

Why: when power returns it can come back with brief spikes and dips, and every motor and compressor in the house trying to start in the same second pulls a large current at once. Unplugged electronics cannot be harmed by a spike, and a house that restarts its loads one at a time is easier on the equipment and on the circuit.

Step 5: Use flashlights, not candles

Battery flashlights and lanterns, with spare batteries, are the light source. Candles cause house fires in outages because they are placed in unfamiliar spots, near curtains, left in a room nobody is in, or knocked over in the dark by a child or a pet. If you must use one, keep it in a sturdy holder on a clear surface, never leave the room while it burns and put it out before anyone goes to sleep.

Step 6: Keep fuel-burning heat and power outside

When it is cold, the temptation is to use whatever burns for warmth. Do not:

• use a gas range or oven to heat the house;
• bring a charcoal or gas grill, a camp stove or a camp heater inside, including into a garage with the door up;
• run a portable generator in the house, the basement, the garage or a crawlspace, or near a window, door or vent. Keep it outside, at least 20 ft from the house as the U.S. Centers for Disease Control and Prevention advises, with the exhaust pointed away from the house and any neighbor's windows.

All of these make carbon monoxide, which you cannot smell. Make sure your CO alarms have working batteries (hardwired alarms have a battery backup for exactly this), and if one sounds, get everyone out. See related: How to Respond When Your Carbon Monoxide Alarm Goes Off.

Never connect a generator to the house by plugging it into a wall outlet or a dryer outlet. That sends power backward out through your service to the utility lines, where it can electrocute a line worker, and it can start a fire in your house. The only safe way to power house circuits from a generator is a transfer switch or interlock installed by an electrician, licensed where your state or locality licenses that work. See related: Portable Generators and Your House: What Is Safe.

Step 7: Watch the systems that stop when the power does

• Sump pump. If your basement relies on one, it stops in an outage, usually during the same storm that is filling the pit. Check the pit. A battery backup pump buys hours. See related: How Your Sump Pump Protects Your Basement.
• Well pump. No power, no water on a private well. Fill pitchers and the bathtub before a predicted storm.
• Garage door opener. It will not open. The red cord on the opener releases the door so it can be lifted by hand; pull it only with the door fully closed, because a door that is partly open can drop when released.
• Pipes in winter. A long winter outage lets a house cool to the point where pipes freeze. See related: How to Handle a Frozen Pipe Before the Plumber Arrives.

Step 8: When the power comes back, restart big loads one at a time

When the lamp you left on comes back, wait a few minutes to see whether the power holds. Then turn on the thermostat first and let the heating or cooling start. After a minute or two, turn on the next big load: the water heater if it is electric and has a switch, the washer or dryer, then plug the electronics back in. Check the fridge and freezer thermometers before you decide what food to keep.

If your air conditioner or heat pump does not start, give it a few more minutes; many have a built-in delay after a power loss. If it still does not run, check the breaker once. If it trips again, leave it off and call a heating and cooling contractor.

A worked outage: the food clock

The setup: a summer thunderstorm. The power goes out at 4:30 p.m. The utility's text says the estimated restoration is 2:00 a.m. The freezer is packed full. The fridge has milk, chicken for dinner, leftovers and a bottle of insulin.

4:35 p.m. The family notes the time and the fridge clock: it will be about 4 hours safe if they keep it shut, so until about 8:30 p.m. The estimated restoration is past that, so before closing it again, they move the insulin, the milk and the chicken into a cooler packed with frozen bottles from the freezer. The freezer door is open for under a minute and then stays shut.

4:40 p.m. Electronics unplugged, the thermostat off, the washer switched off, one lamp left on in the hall.

1:40 a.m. The hall lamp comes on. Total time without power:

4:30 p.m. to 12:30 a.m.  =  8 h 00 min
12:30 a.m. to 1:40 a.m.  =  1 h 10 min
total                     =  9 h 10 min
check: 4:30 p.m. is 16:30, 1:40 a.m. next
       day is 25:40; 25:40 minus 16:30 = 9:10

They wait five minutes, the power holds, the thermostat goes on, and five minutes later everything else comes back one item at a time.

The fridge: its thermometer reads 47 F. The family does not know when it passed 40 F, only that it was safe until about 8:30 p.m. and has been warming since. Over 9 hours without power, more than 5 hours past the 4-hour mark, it has almost certainly been above 40 F for more than 2 hours. The leftovers and other perishables in the fridge go out. Hard cheese, butter and unopened condiments can usually stay; the USDA's food safety chart lists which items are which, and it is worth looking up rather than guessing. The insulin went into the cooler at 4:35, so it stayed cold; for medication, follow the label or ask the pharmacist.

The freezer: it was full, so its guide was about 48 hours. The thermometer reads 10 F and the food is still frozen hard. Food that still has ice crystals or reads 40 F or below can be refrozen, so all of it stays.

What would have changed the answer: if the freezer had been half full, its guide would have been about 24 hours, still comfortably longer than this 9-hour 10-minute outage. If the outage had run past the next afternoon, the half-full freezer would have been the one to check first. And if the family had opened the fridge every hour to "check on it", the 4-hour guide would not have held at all.

References

• U.S. Department of Agriculture, Food Safety and Inspection Service guidance on keeping food safe during a power outage (the 4-hour, 48-hour, 24-hour and 40 F for 2 hours figures)
• U.S. Centers for Disease Control and Prevention guidance on generator placement and carbon monoxide
• See related: Portable Generators and Your House: What Is Safe
• See related: How to Reset a Tripped Breaker Once
• See related: When to Stop and Call a Licensed Pro Around the House