How do you prepare for a long power outage?

Short answer. Keep the fridge and freezer closed: food stays cold about 4 hours in a refrigerator, 48 hours in a full freezer and 24 in a half-full one ¹. Discard perishables held at 40°F (4°C) or above for two hours or more ². Plan for powered medical devices and refrigerated medicines ⁶, and run generators outdoors, at least 20 feet (6 m) from windows and doors ²⁶.

How long is food in the fridge and freezer safe without power?

The U.S. figures are short and specific. With the door kept closed, a refrigerator keeps food cold for about 4 hours; a full freezer holds its temperature for about 48 hours, and a half-full freezer about 24 hours ¹. Canada gives a range of 24 to 48 hours for a full freezer with the door kept closed ⁶.

The FDA asks you to keep the refrigerator at or below 40°F (4°C) and the freezer at or below 0°F (−18°C), and to keep an appliance thermometer in each so you can check them after the outage ¹. That thermometer is what turns a guess into a decision.

When the power comes back, Canada advises restoring heating thermostats first, then the fridge and freezer, and waiting 10 to 15 minutes before reconnecting other appliances ⁶.

What if someone depends on a medical device or refrigerated medicine?

This is the part of an outage plan that cannot be improvised. Ready.gov says to talk to your medical provider about a power outage plan for medical devices ², and Canada recommends a separate plan for electrically powered medical devices, refrigerated medicines and equipment that depends on the internet ⁶.

The FDA lists concrete steps ⁴:

• Tell your electric company and fire department that you use a device that needs power, such as a ventilator or apnea monitor.
• Read the user instructions or call the distributor or manufacturer to learn whether the device can run on batteries or a generator.
• Before plugging a device back in, check for water; do not plug in a cord or device that is wet.
• When power returns, check that the device settings have not changed.

In Great Britain, network operators must offer extra help during planned and unplanned cuts to customers on the Priority Services Register, for example battery packs to charge phones or medical equipment; what each company offers differs ⁹.

For medicines, the guidance differs by product. Ready.gov says that if the power is out for more than a day, you should discard medication that should be refrigerated, unless the label says otherwise ². Insulin is one documented exception: the FDA says manufacturer vials and cartridges may be left unrefrigerated between 59°F and 86°F (15–30°C) for up to 28 days ⁵. Check each label and ask a pharmacist before relying on either rule.

How do you stay warm without electricity?

Agencies agree on two points: use what you have safely, and never improvise with fuel indoors.

• Gather in one room. Sweden's advice is to choose a room where the family can gather, add extra rugs and seal gaps around windows and doors ⁸. Germany notes that warm clothing and blankets can partly replace heating, and recommends keeping the room closed while still ventilating regularly ⁷.
• Plan an alternative heat source in advance, with an expert. The BBK suggests checking whether an alternative heat source can be installed in your home and getting professional advice; for gas heaters, it asks that the device have oxygen-deficiency and ignition safeguards ⁷. Installation is a job for a qualified installer, not a weekend project.
• Do not heat with a gas stove or oven. Ready.gov says not to use a gas stove or oven to heat your home ², and Canada says a natural gas stove can be used for cooking but not as a heating source ⁶.
• Leave when it is too cold or too hot. Ready.gov advises going to a community location with power if heat or cold is extreme, and checking with local officials which heating or cooling locations are open ².

In winter, Canada also advises draining water from the plumbing to prevent freezing, and making sure the hot water heater is filled before the power is turned back on ⁶.

How do you avoid carbon monoxide poisoning?

Carbon monoxide is the hazard that turns an inconvenience into an emergency. In the United States, more than 400 people die each year from unintentional CO poisoning not linked to fires, more than 100,000 visit an emergency department and more than 14,000 are hospitalized ³.

• Run generators outdoors, more than 20 feet from windows, doors and vents ³. Canada uses at least 6 m (20 feet) from homes or buildings, with the exhaust pointed away from windows and doors ⁶.
• Never run a generator inside a home or garage, even with doors and windows open ³.
• Never burn charcoal indoors ³; Germany warns against grilling inside a house or apartment because of the risk of suffocation ⁷.
• Install carbon monoxide detectors with battery backup in central locations on every level of the home ². Germany also recommends a CO detector ⁷.
• If you use candles for light, ventilate regularly ⁷.

What should you do before the next outage?

• Charge and store power. Keep phones and laptops charged, or have spare batteries; power banks and solar chargers can help ⁷.
• Keep a radio. A battery or hand-crank radio receives official announcements during a long outage ⁷. In Sweden, the instruction is to listen to Sveriges Radio P4, using a car radio if necessary ⁸.
• Keep some cash. ATMs may not work during an outage ⁷.
• Fuel or charge the car. Canada advises keeping the gas tank at least half full, or an electric vehicle charged, when an outage is likely ⁶.
• Store water. Water can stop flowing when the power is out ⁷. Sweden says that if an outage has lasted more than an hour, you should fill bottles or containers from the tap, allowing a couple of litres per family member ⁸.
• Plan cold meals. Germany suggests long-life foods that can be eaten cold and a camping stove for small meals; a charcoal or gas grill belongs in the garden or on the balcony, never indoors ⁷.
• Know who to call. In the UK, call 105 free of charge to reach your electricity network operator ⁹.

What official agencies recommend

The British regulator also sets restoration standards for England, Scotland and Wales: network operators must restore supply within 12 hours outside severe weather, 24 hours in category 1 storms and 48 hours in category 2 storms, depending also on how many homes are affected, with compensation payable when these are missed ⁹. That 48-hour figure is a useful planning horizon, not a guarantee.

Frequently asked questions

Can I refreeze food that partly thawed?

Yes, if it still contains ice crystals or is at 40°F (4°C) or below; the FDA says it is safe to refreeze or cook ¹. Otherwise, follow the two-hour rule above 40°F and discard it ².

How far from the house should a portable generator be?

At least 20 feet (6 m). The CDC says more than 20 feet from windows, doors and vents ³, Ready.gov says at least 20 feet from windows, doors and attached garages ², and Canada says at least 6 m from homes or buildings ⁶.

Is it safe to use the gas oven to heat the kitchen?

No. Ready.gov says not to use a gas stove or oven to heat a home ², and the Government of Canada says not to use a natural gas stove as a heating source ⁶.

What happens to insulin during a long outage?

Manufacturer vials and cartridges may be kept unrefrigerated between 59°F and 86°F (15–30°C) for up to 28 days, according to the FDA ⁵. Other refrigerated medicines may not tolerate that, so check the label or ask a pharmacist ².

Who should I call to report a power cut in the UK?

Call 105, which is free and puts you through to your electricity network operator; you can also report the cut on your network operator's website ⁹.

Next step: write your outage plan

A long outage tests the details: who needs power for health, where the warm room is, and which food to eat first. Official advice differs by country, so write these decisions down for your household. See the Phaenyx plan.

Sources

1. U.S. Food and Drug Administration — Food and Water Safety During Power Outages and Floods — https://www.fda.gov/food/buy-store-serve-safe-food/food-and-water-safety-during-power-outages-and-floods (accessed 2026-10-20)
2. Ready.gov (U.S. Department of Homeland Security / FEMA) — Power Outages — https://www.ready.gov/power-outages (accessed 2026-10-20)
3. Centers for Disease Control and Prevention — Carbon Monoxide Poisoning Basics — https://www.cdc.gov/carbon-monoxide/about/index.html (accessed 2026-10-20)
4. U.S. Food and Drug Administration — FDA Offers Tips about Medical Devices and Natural Disasters — https://www.fda.gov/medical-devices/emergency-situations-medical-devices/fda-offers-tips-about-medical-devices-and-natural-disasters (accessed 2026-10-20)
5. U.S. Food and Drug Administration — Information Regarding Insulin Storage and Switching Between Products in an Emergency — https://www.fda.gov/drugs/emergency-preparedness-drugs/information-regarding-insulin-storage-and-switching-between-products-emergency (accessed 2026-10-20)
6. Government of Canada — Power outages - Get prepared — https://www.canada.ca/en/services/policing/emergencies/preparedness/get-prepared/hazards-emergencies/power-outages/how-prepare.html (accessed 2026-10-20)
7. Bundesamt für Bevölkerungsschutz und Katastrophenhilfe (BBK), Germany — Vorsorge und Handeln bei Stromausfall — https://www.bbk.bund.de/DE/Warnung-Vorsorge/Vorsorge/Stromausfall/stromausfall_node.html (accessed 2026-10-20)
8. Krisinformation.se, Sweden — Checklist for before, during and after a power cut — https://www.krisinformation.se/en/hazards-and-risks/power-cuts (accessed 2026-10-20)
9. Ofgem, United Kingdom — Check if you can get a payment for a power cut — https://www.ofgem.gov.uk/information-consumers/energy-advice-households/plan-power-cut (accessed 2026-10-20)