The first 30 minutes of a power outage set up how bad the next 12 hours will be. People who do the right handful of things early keep their food, their devices, and their sanity; people who do nothing lose all three. This is the short checklist that matters, in order, plus the size-and-runtime question at the end.
The First 10 Minutes
- Confirm it's a real outage. Check whether a breaker tripped (the rest of the street is dark, or your neighbors have power — that's a panel or service issue, not a utility outage).
- Report it to your utility through their app or phone line. Many utilities have an outage map; reporting helps them locate faults faster.
- Leave one light switch on so you know when power returns. Turn off the rest.
- Grab flashlights, not candles. Candles cause house fires during outages every year. A headlamp or phone flashlight is safer and brighter.
- Leave the fridge and freezer doors closed. This is the single biggest food-saving action. A closed refrigerator holds a safe temperature for about 4 hours; a full, closed freezer holds for about 48 hours (24 hours if half full). Every opening cuts that sharply. Decide what you need once, take it out, close the door.
- Turn off or unplug sensitive electronics — computers, TVs, modem (after you've grabbed any cached info), microwave, anything with a circuit board. When power returns, a surge can fry unprotected devices. Leave one lamp on so you see the return.
The Next 30 Minutes
- Turn off the main water supply if you're on a well pump. Without power, well pump pressure tanks deliver only their reservoir; once that's drained, you're out. Conserve what's in the tank.
- If you have a generator, set it up outdoors and away from windows. See our generator sizing guide if you're buying one; running a portable generator is covered in generator vs. battery.
- Fill a bathtub with water if you're on a well — this is your toilet-flushing and cleanup reserve for the next day.
- Check on neighbors, especially anyone elderly, with a disability, or with small kids. A 30-second knock saves lives, especially in heat waves and cold snaps.
- If anyone uses powered medical equipment (CPAP, oxygen concentrator, dialysis), switch to your backup plan and call your utility — most utilities maintain a medical-priority list that can speed restoration or send help.
Keeping Food Safe
The 4-hour / 48-hour rule above assumes closed doors. Beyond that, the key metric is temperature, not time:
- Fridge: Safe below 40°F. Once it rises above 40°F for more than 2 hours, perishables (meat, dairy, leftovers, cut fruit) should be discarded. Condiments and most uncut produce usually survive.
- Freezer: Safe while the food still has ice crystals. A half-full freezer keeps food ~24 hours; a full one ~48. If anything has fully thawed and been above 40°F for 2+ hours, throw it out.
- When in doubt, throw it out. Food poisoning during a disaster is a common and entirely avoidable problem.
A refrigerator / freezer thermometer (a $5 appliance thermometer) is the only way to actually know — guesswork isn't reliable and people lose food they could have saved or keep food they shouldn't.
Keeping Your Phone and Information
- Conserve battery aggressively: lower screen brightness, close background apps, disable push for nonessential apps, enable low-power mode.
- Text, don't call when the network is overloaded — texts get through when calls can't.
- Use your car as a phone charger if your power bank is dead (with the car running, in a ventilated spot — never in a closed garage).
- Keep a battery or crank radio for news and weather when the cell network is unreliable. NOAA weather radio is reliable for official announcements.
If a radio, satellite messenger, or mesh device is part of your plan, our offline communication gear guide covers what actually works once the towers are down or overloaded.
Staying Warm (or Cool)
Cold outages are more dangerous than people expect:
- Dress in layers; a hat matters more than people think.
- Gather in one room and close it off. Heating one small space is far easier than a whole house.
- Use blankets and sleeping bags; add cardboard or rugs against cold floors.
- Never use a gas oven, grill, camp stove, or generator indoors for heat. Carbon monoxide is invisible, odorless, and kills fast. This is the most repeated and most ignored safety rule in every outage.
- Stay hydrated — you lose moisture to cold, dry winter air faster than you'd think.
Hot outages are dangerous for older adults and small kids:
- Stay hydrated; move activities to early morning or evening.
- Close curtains and blinds on windows facing the sun to cut heat gain dramatically.
- Use a damp cloth on the neck and wrists as a low-tech cooldown.
- Identify a cooling center or air-conditioned public space (library, mall) if your home becomes unsafe, and go before you're in trouble, not after.
When to Call It
Most outages are short — under 4 hours, often under an hour. But when is the outage long enough to act on the bigger questions?
- Past ~4 hours: Start managing fridge use carefully; if you have a portable cooler and ice, move high-priority perishables to it.
- Past ~12 hours (overnight): If it's cold and you don't have heat, this is when vulnerable people (elderly, infants, medical needs) start to be at real risk. Decide whether to relocate to a warming/cooling center or a friend's home.
- Past ~24 hours with no restoration estimate, or with an estimate >24h: This is when people start seriously asking about generators and batteries. If you're at this point repeatedly, the right move is to plan backup power before the next outage — our backup power calculator will tell you exactly what size and cost fits your home.
- Past 48 hours: Food in a half-full freezer is likely no longer safe to rely on without checking. Re-evaluate whether to ride it out or relocate.
If your region experiences frequent, multi-day outages, that's the moment when investing in a generator or home battery stops being a luxury and starts being the sensible decision. Use the calculator to find the right size and cost for your specific home instead of guessing.
What Not to Do
- Never run a generator, grill, camp stove, or gas oven indoors or in a garage.
- Don't open fridge/freezer doors to "check" — that's the whole game.
- Don't plug a generator directly into your home's wiring unless you have a properly installed transfer switch — it can backfeed the grid and kill a lineman.
- Don't rely on the elevator if you have another option.
The One-Paragraph Version
Lights out? Don't open the fridge. Leave one lamp on, unplug the computers, grab flashlights. If anyone uses medical equipment, execute your backup plan now and call the power company. If it's cold, gather in one room in layers and never use any flame or fuel-burning device indoors. Text instead of calling to save bandwidth and battery. Check on your neighbors. If this is your third long outage in a year, it's time to calculate the backup power that fits your home — being prepared in advance is dramatically easier than improvising each time.
When the outage isn't weather-related: a cyberattack or a major cloud failure can keep the lights off longer than a storm, with a less predictable restoration timeline. See grid cyberattack prep and internet outage preparedness.