Power outage playbook

Food safety decisions during an extended power outage are driven by one principle: the bacterial growth curve in the food temperature danger zone (40°F to 140°F). Below 40°F, bacterial growth slows to safe rates. Above 140°F, sustained heat kills bacteria. Between those temperatures, bacteria double approximately every 20 minutes. The FDA and USDA guidelines exist to reflect this biology; they are not arbitrary.

• Refrigerator: 4-hour safe window: A refrigerator that is kept closed will maintain 40°F for approximately 4 hours after power loss. Every time the door is opened, that window shortens; cold air falls out immediately when the door is opened. After 4 hours without power, the interior temperature has typically risen above 40°F and perishable foods (meat, poultry, fish, dairy, eggs, cut fruits and vegetables, cooked leftovers) begin accumulating bacterial load. After 4 hours, use or discard perishables. Do not rely on smell or appearance as safety indicators, since the bacteria that cause foodborne illness do not produce detectable odors in early growth phases.
• Freezer: 24 to 48 hour window (if kept closed): A full freezer maintains safe temperatures for approximately 48 hours; a half-full freezer for approximately 24 hours. The thermal mass of frozen food is significant; a packed freezer is its own insulation. Do not open the freezer during the outage. Food that still contains ice crystals and has been kept at 40°F or below is safe to cook and eat or safe to refreeze. Food that has completely thawed and been above 40°F for more than 2 hours should be discarded. Refreezing partially thawed food that has remained cold enough is safe, though texture will degrade.
• Never taste-test for safety: The bacteria responsible for most food poisoning (Salmonella, E. coli, Listeria, Staphylococcus aureus) are not detectable by taste, smell, or appearance at infectious concentrations. Food that smells and looks fine can cause severe foodborne illness. The "when in doubt, throw it out" guidance from the USDA is not precautionary overcaution; it reflects the inability of human sensory assessment to detect the relevant pathogens.
• Foods that are safe at room temperature: Shelf-stable items require no refrigeration and are unaffected by power outages: canned goods, commercially packaged crackers, peanut butter, jam, honey, hard cheeses in sealed wax, dried fruits, nuts, trail mix, cereals, bread, and fresh fruits and vegetables that have not been cut. Build your outage meal plan from these items and refrigerator/freezer food that is clearly within the safety window, in that order.
• Keep a refrigerator thermometer: An inexpensive appliance thermometer stored in the refrigerator tells you the actual temperature when power returns. This eliminates guesswork about whether the refrigerator maintained safe temperature during the outage. Without a thermometer, you are making safety decisions based on elapsed time estimates, which are imprecise. With a thermometer, you have an objective data point.

Heating failure is the primary life safety risk in cold-weather power outages, particularly for elderly individuals, infants, and anyone with cardiovascular or respiratory conditions. Hyperthermia from extended heat without air conditioning is an equally serious risk in hot climates. Both require a plan before the event, not improvisation during it.

• Layering and shelter-in-place for cold: The simplest cold-weather response is consolidating everyone into one small room (a bedroom, not an open-plan living area), closing all doors to concentrate body heat, hanging heavy curtains or blankets over windows to reduce drafts, and using sleeping bags rated for below the anticipated low temperature. Modern sleeping bags rated to 0°F are effective to well below their rating for stationary individuals. This approach requires no fuel, has no safety risks, and can maintain survivable temperatures in a well-insulated home even in significant cold.
• Indoor-safe propane and kerosene heaters: Certain portable heaters (Mr. Heater Buddy, for example, in the propane category) are rated for indoor use with adequate ventilation, at minimum one window cracked one inch. These heaters include oxygen depletion sensors that shut off the unit if oxygen levels drop. They are not risk-free, but they are meaningfully safer than unventilated combustion sources. Read and follow the specific manufacturer's ventilation requirements for your model. Never use heaters designed for outdoor use (patio heaters, construction heaters, propane burners) indoors under any circumstances.
• Never use ovens, gas ranges, or charcoal grills for heating: Gas ovens produce carbon monoxide. Charcoal grills produce lethal concentrations of carbon monoxide indoors; a single charcoal grill burning in a closed house has killed entire households. These are not theoretical risks or edge cases. Carbon monoxide is odorless and colorless; there is no sensory warning before incapacitation. A working battery-powered carbon monoxide detector is the only protection against an undetected CO buildup. If your CO detector alarm sounds, evacuate immediately and call 911.
• Heat emergency in warm climates: Core cooling centers (libraries, malls, community centers) typically open during extended outages in heat emergencies, coordinated by local emergency management. Know the nearest cooling center to your home before summer. For cooling in place without grid power: a portable battery fan is significantly more effective than people expect at wind-chill; damp cloths or sheets reduce radiated heat; basements are typically 10 to 15°F cooler than living areas; shading windows facing afternoon sun with exterior coverings before the heat peaks substantially reduces indoor temperature rise. Hydration becomes critical; adults need significantly more water than normal in heat stress conditions, particularly elderly individuals and children.
• Whole-house generators and transfer switches: A permanently installed whole-house standby generator with an automatic transfer switch restores power to the house within seconds of an outage and eliminates most of the heating, food safety, and medical equipment concerns. Installation requires a licensed electrician and, for natural gas models, a gas line connection. Installation alone typically costs $1,512 to $8,803, with most homeowners paying around $5,157 (HomeAdvisor); the generator itself is extra. Portable generators with a manual transfer switch are an effective alternative at lower cost but require manual startup and fuel management. See the generator safety section below.
  Pro recommended: Licensed Electrician

• Cold: consolidate into one small room + closed doors + heavy curtains on windows + sleeping bags rated below anticipated low. No fuel, no safety risk.
• Indoor-safe heaters (Mr. Heater Buddy propane): rated for indoor use with at minimum one window cracked 1 inch; oxygen depletion sensor included. Never use outdoor heaters (patio, construction, propane burners) indoors under any circumstances.
• Never: gas oven, gas range, or charcoal grill for heating. Charcoal produces lethal CO concentrations indoors. CO is odorless and colorless: no sensory warning before incapacitation. CO detector alarm = evacuate immediately + call 911.
• Heat: know nearest cooling center (library, mall, community center) before summer. Basement typically 10-15°F cooler than living areas. Battery fan + damp cloths + exterior window shading before heat peaks.
• Whole-house standby generator with auto transfer switch: restores power in seconds (installation alone typically $1,512-$8,803, most around $5,157, HomeAdvisor; unit extra). Requires licensed electrician.
  Pro recommended: Licensed Electrician

Portable generators kill people every year, primarily through carbon monoxide poisoning. The mechanism is consistent: a generator is placed in a garage, basement, or near an open window because outdoor placement seems inconvenient. Carbon monoxide accumulates in the structure within minutes. Occupants are incapacitated before they can respond. This is preventable with distance and a CO detector.

• The 20-foot rule, and wattage matters: The CPSC and CDC both specify a minimum of 20 feet between a portable generator's exhaust and any door, window, or vent opening. That 20 feet is a floor, not a universal standard; higher-wattage generators produce more CO and may require greater separation. Your generator's manual is the authoritative source for your specific unit; confirm with your local authority having jurisdiction (AHJ) if your local code sets a stricter standard. In practice, generators should be positioned so that their exhaust is directed away from the structure and any prevailing wind will carry the exhaust further away. A generator running in a detached garage with the door open has killed families; the garage door does not provide adequate ventilation. Do not position generators under decks, in enclosed carports, or near basement windows regardless of distance.
• CO detector placement and state code requirements: Install a carbon monoxide detector on every habitable floor of your home, and specifically near sleeping areas. Most state residential codes require CO alarms near sleeping areas and on each level of any home with an attached garage or fuel-burning appliance. Check your state fire marshal's site or local building department for the specific requirement in your jurisdiction. Replace the batteries when you replace smoke detector batteries (typically annually). A CO detector alarm is not an advisory to open a window; it is an instruction to evacuate the building immediately and call 911 from outside. Carbon monoxide at alarm-threshold concentrations can incapacitate an adult within minutes; the margin between first symptoms and incapacitation is narrow. Do not attempt to locate the source before evacuating.
• Transfer switch requirement: Connecting a portable generator directly to your home's wiring (backfeed connection) without an approved transfer switch is illegal in most jurisdictions and creates two hazards: it can energize utility lines and electrocute utility workers attempting to restore power, and it bypasses the circuit breaker protection in your panel. The correct connection method is an interlock kit or manual transfer switch installed by a licensed electrician, or use of heavy-duty extension cords connected directly to the generator's outlets for individual appliances. The extension cord method is less convenient but requires no electrical installation.
  Pro recommended: Licensed Electrician
• Fuel storage and runtime planning: Calculate your generator's runtime per gallon at your expected load level (generator manufacturers publish this at 25% and 50% load; most household loads during an outage fall in this range). For a 72-hour outage, calculate the gallons needed and store that quantity in approved containers treated with a fuel stabilizer if stored more than 30 days. Rotate stored fuel every 6 to 12 months; gasoline with ethanol degrades faster than gasoline without. Store fuel in a detached garage or shed, not inside the house. Mark storage containers with the fill date.
• What to power, priority order: Sump pump (if in a flood-prone area) prevents basement flooding, which has long-term structural and mold consequences. Refrigerator and freezer protect food supply. Heating or cooling equipment (window AC, space heater with transfer switch) manages temperature safety. Medical equipment (CPAP, oxygen concentrator). Lighting and communication. Running a generator at maximum load to power all normal appliances simultaneously shortens runtime and increases fuel consumption significantly; load-shedding to priority items extends runtime proportionally.

• 20-foot minimum from any door, window, or vent opening (CPSC / CDC baseline: higher-wattage units may require more; confirm against your unit's manual and local AHJ). Exhaust directed away from structure and with prevailing wind. Detached garage with door fully open = still not adequate ventilation. No decks, enclosed carports, or near basement windows.
• CO detector: every habitable floor + near sleeping areas. Most state codes require this for any home with an attached garage or fuel-burning appliance; check your state fire marshal or local building department for the exact requirement. Batteries current. Alarm = evacuate immediately + call 911 from outside. Do not attempt to locate the source first.
• Backfeed without transfer switch = illegal in most jurisdictions + electrocution risk for utility workers. Correct method: interlock kit or manual transfer switch (licensed electrician), or heavy-duty extension cords direct to generator outlets.
  Pro recommended: Licensed Electrician
• Fuel: calculate runtime at expected load (25-50%); store 72-hr supply in approved containers + stabilizer if stored over 30 days. Rotate every 6-12 months. Detached garage or shed only. Fill date marked on containers.
• Priority order: sump pump → fridge/freezer → heat or AC → medical equipment → lighting and communication. Load-shedding to priority items extends runtime proportionally.

Water service and communications are the two systems that most people do not plan for until they fail. Both have straightforward backup strategies that require minimal preparation cost.

• Stored water: FEMA's recommendation of one gallon per person per day for drinking and basic sanitation is the accepted planning figure. Store a minimum 72-hour supply (3 gallons per person) in food-grade containers; commercially bottled water is simplest. Replace water you stored yourself every 6 months (Ready.gov), or follow the expiration date on commercial bottles. For extended outage planning beyond 72 hours, a larger stored volume or a water purification method is necessary. During the outage, if tap water service is disrupted, do not use water from the water heater tank without boiling or treating it first; it may contain sediment and bacteria from sitting in the tank.
• Treating tap water: If the local water utility issues a boil-water advisory (common during and after major flooding events when water main pressure drops), treat all water used for drinking, cooking, making ice, and brushing teeth. Rolling boil for 1 minute (3 minutes above 6,500 feet elevation) is the standard treatment per the CDC. Alternatively, use NSF-certified filtration rated for bacteria removal plus halogen tablets for viral coverage, or UV treatment in clear water. A boil-water advisory that is issued may remain in effect for days. Have a plan to treat water for that duration, not just the first 24 hours.
• Toilet function without electricity: Most residential toilets function normally during a power outage; they use gravity and stored water in the tank, not electrical power. The exception is homes with a sewage lift station (common in low-elevation or rural properties). If the lift station loses power, sewage cannot be pumped away. After 1 to 2 toilet flushes, the system backs up. Know whether your home uses a lift station, and if so, limit toilet use to absolutely necessary flushes during an extended outage and have a plan for waste management if the station is offline for more than 12 to 24 hours.
• Lighting: LED headlamps with long battery life (Black Diamond, Petzl) are the highest-utility lighting tool for outage conditions. Rechargeable models can be topped off by a power bank or generator. Keep two per household: one primary, one backup. Chemical lightsticks (glowsticks) are an effective ambient-light supplement with no battery requirement, a 4-year shelf life, and no fire risk. Store a dozen per household and replace at the 4-year mark. Candles are a significant fire risk during outages, particularly with disoriented family members moving around unfamiliar spaces in the dark; if candles are used, do not leave them unattended and keep a fire extinguisher accessible.
• Staying informed: A battery-powered or hand-crank NOAA Weather Radio is the most reliable information source during a regional outage. It broadcasts official NWS bulletins, local emergency management announcements, and shelter information continuously and does not require internet or cell connectivity. Local AM radio stations (emergency alerting law requires broadcasters to carry official alerts) are a secondary source that provides more local context. Check your phone's charge status early in the outage and prioritize communication use over entertainment; a fully charged phone lasts significantly longer when not streaming video or running background apps.