Blackout response: first 72 hours

Per US Energy Information Administration (EIA) data, US households averaged 5.6 hours of power interruption in 2022. That figure hides the tail: during major hurricane, winter storm, and wildfire events, outages routinely stretch 3–14 days. Most people experience a 24–72-hour outage at least once every three to five years — and the first 72 hours determine whether it stays a controlled inconvenience or escalates into a food-loss, medication, or heat injury emergency.

The window between "lights off" and "nothing I can do" is shorter than most people expect. A refrigerator full of meat becomes a biohazard in four hours if you keep opening it. Insulin loses viability at room temperatures above 86°F (30°C). Cell towers run on generator backup for roughly eight hours before the signal degrades. Every hour in the first day matters.

Carbon monoxide kills more people than the outage itself

Per CDC and CPSC data, nearly 100 people die in the US each year from generator CO poisoning — most during weather-related outages. CO is odorless, colorless, and lethal within 2–3 hours at 800 ppm.

Run all generators outdoors only, at minimum 20 feet (6 m) from any window, door, or vent per CPSC guidance
Never run a generator in a garage, even with the door open
Never bring a propane heater, camping stove, or charcoal grill indoors as a heat or cooking substitute
Install at least one battery-backed CO alarm rated to UL 2034 on every occupied floor
If a CO alarm activates: evacuate immediately, call 911 from outside, do not re-enter

Before you start

Skills: Basic understanding of your home electrical panel — which breakers control which loads, and where the main disconnect is. Familiarity with your refrigerator and freezer door seals (a failing gasket bleeds cold air even when "closed").

Materials: Flashlight or headlamp with fresh batteries on every floor; a battery-backed or hand-crank NOAA Weather Radio (e.g., Midland ER310 or equivalent); appliance thermometer in the refrigerator (target ≤40°F / 4°C) and freezer (target ≤0°F / –18°C) so you can make keep-or-discard decisions with data, not guesses; a supply of potable water at 1 gallon (3.8 L) per person per day for at least 3 days per FEMA Ready.gov; a cooler and frozen gel packs or ice for medication cold-chain preservation; at least 14 days of prescription medications on hand per rolling-supply practice (see medical stockpiling); a designated out-of-area contact the entire household can reach to confirm status.

Conditions: Check the CO alarm battery and test function monthly. Verify generator fuel supply quarterly and run the generator under load for 30 minutes every 90 days so you know it starts when you need it.

Time: The triage steps below take 20–30 minutes to execute. Follow-on monitoring and decision points span the full 72-hour window.

Hour 1: Triage and safety

The first hour is not a comfort exercise — it is a damage-control sequence. Run through this in order:

Verify the outage scope. Check your circuit breaker panel — a single tripped breaker means a local fault, not an outage. If the whole house is dark, look out the window for neighboring homes. If the outage appears neighborhood-wide or broader, call your utility's non-emergency outage number or check their outage map via mobile data. Knowing the scope (block vs. city vs. regional grid failure) immediately shapes your timeline planning. Per FEMA Ready.gov power outage guidance, this determination drives everything else.
Kill non-critical loads. Go to your electrical panel and turn off or unplug computers, televisions, gaming consoles, and other electronics. When grid power returns, it often comes back with a surge that can damage sensitive equipment. Leave one or two lights switched on at the panel so you know the moment power is restored.
Close the refrigerator and leave it closed. An unopened refrigerator maintains safe temperature (≤40°F / 4°C) for approximately four hours per USDA FSIS food safety guidance. Every time you open the door, you lose cold air and shorten that window. If the outage is likely to last more than four hours, move to the Day 1 food management section immediately.
Confirm medical-device backup is operational. If anyone in your household uses a CPAP, BiPAP, home oxygen concentrator, nebulizer, or powered wheelchair, verify that their backup power source — battery, UPS, or portable power station — is active and has sufficient charge for the expected outage duration. A CPAP typically draws 30–60 watts; a 500 Wh portable power station provides roughly 8–15 hours of runtime at that load. See portable power stations for sizing guidance.
Identify vulnerable household members. Anyone over 65, under five, or with heat- or cold-sensitive medical conditions needs explicit monitoring through the outage. Check their room temperature every two hours during extreme weather.
Check on neighbors — especially the elderly and those with medical equipment. An outage that is minor for a healthy adult may be life-threatening for someone who relies on powered medical equipment or cannot self-regulate temperature. A knock on the door in hour one costs two minutes and may prevent a 911 call in hour twelve.

Field note

Tape a sticky note to your refrigerator door reading the outage start time before you walk away. When you return six hours later wondering "is this food still safe?", the note gives you an exact answer instead of a guess.

Day 1 (hours 1–24): Food and medication preservation

Food safety and medication cold-chain management are the two highest-consequence decisions in the first 24 hours. Both have time clocks running the moment power drops.

Refrigerator management

The key rule from USDA FSIS: discard perishables after 4 hours above 40°F (4°C). This applies to raw meat, poultry, seafood, dairy, eggs, and any cooked leftovers. Condiments, hard cheeses, and whole fruits and vegetables tolerate longer periods at elevated temperatures.

Keep the door closed. Full stop. Every opening costs you cold air.
Use your appliance thermometer, not guesswork, to decide when the threshold is crossed.
If you have access to ice, move the most critical perishables — meat, dairy, eggs — into a cooler with ice and a lid that seals.

The USDA FoodKeeper App provides item-specific guidance if you need to triage a specific food. When in doubt about any protein item: discard it. Food poisoning from Salmonella or Staph toxin in a grid-down situation is a serious secondary emergency.

Freezer management

A fully loaded freezer holds safe temperature (≤0°F / –18°C) for approximately 48 hours with the door kept closed, per USDA FSIS data. A half-full freezer holds for approximately 24 hours. Food that still contains ice crystals or reads ≤40°F (4°C) on a thermometer can be refrozen or cooked. Do not rely on smell or appearance alone — some dangerous bacteria produce no detectable change in odor or texture.

If the outage may extend beyond 48 hours, dry ice is your primary option:

Dry ice quantity	Freezer capacity	Approximate hold time
25 lb (11 kg)	10 cu ft (0.28 m³) partial load	~24 hours
50 lb (23 kg)	18 cu ft (0.5 m³) full load	~48 hours
50 lb (23 kg)	20 cu ft (0.57 m³) full load	~4 days

Handle dry ice with insulated gloves — direct skin contact causes frostbite within seconds. Place dry ice on top of frozen food (cold sinks); do not let it contact bare skin, bare bottles, or canned goods that may rupture from freezing. Dry ice sublimes into CO2 — ensure the room has ventilation before working with large quantities.

Medication and insulin cold-chain

Temperature-sensitive medications include insulin (all types), biologics, certain eye drops, and some liquid antibiotics. Check your medication packaging for "store at 36–46°F (2–8°C)" — that is your cold-chain indicator.

Insulin: Per FDA emergency insulin guidance, an unopened insulin vial or cartridge may be kept at room temperature — 59–86°F (15–30°C) — for up to 28 days without losing efficacy. An opened vial at room temperature follows the same 28-day window for most products, but verify your specific product's labeling. Above 86°F (30°C), insulin degrades faster; discard and replace when refrigeration is restored if it was exposed to high heat.

Practical cold-chain action (first hour):

Move insulin to an insulated bag or cooler with two or three frozen gel packs.
Do not allow insulin to contact ice or frozen packs directly — wrap in a cloth layer to prevent freezing (frozen insulin is damaged and must be discarded).
Target ≤46°F (8°C) inside the cooler; check with a thermometer every 4–6 hours.
A quality 10-quart (9.5 L) cooler with a full set of frozen gel packs typically holds 36–48 hours in a temperate indoor environment.

Other controlled medications: Maintain a running log of what medications are time-sensitive. Most solid-form antibiotics, blood pressure medications, and allergy medications are stable at room temperature for 30+ days if stored away from heat and humidity. See medication stockpiling for the full shelf-life reference table.

Track all food and medication decisions in a written log with timestamps. This record supports insurance claims — most US homeowner and renter policies include food-spoilage coverage with a typical sublimit around $250–$500; your insurer will ask for documentation.

Day 2 (hours 24–48): Communication and extended safety

By the second day, the immediate triage is done. Attention shifts to information management, fuel conservation, and keeping everyone safe through a second night.

Communications priorities

The information environment during a major outage degrades faster than most people expect:

Cell towers: Carrier backup-power varies by site — typically a few hours of battery, occasionally hardened generator backup. The 2007 FCC 8-hour backup-power mandate was vacated by OMB in 2008 and never went into effect, so there is no federal floor. During major events, county-level cell tower outage rates have reached 30% or more in affected areas. Treat cell service as intermittent by hour 12.
NOAA Weather Radio: This is your most reliable official information source during an outage. The National Weather Service broadcasts continuously on 162.400–162.550 MHz — a battery-powered or hand-crank NOAA receiver requires no infrastructure except the transmitters, which are maintained on hardened backup power. Program your receiver to the closest transmitter before you need it.
Out-of-area contact check-in: Establish a 24-hour OK signal with your designated out-of-area contact before the outage. The protocol is simple — text or call every 24 hours to confirm status. If the check-in is missed, the contact knows to escalate. See the full communication plan framework at community comms plan.
Local emergency broadcasts: AM radio stations (particularly 550–1700 kHz) carry emergency alerts even when cellular data is congested. A battery or hand-crank radio provides access without mobile data.

Generator runtime management

If you have a generator, fuel is finite. The discipline is to run it only during peak-load windows, not continuously:

Run the refrigerator or freezer for 2–3 hours per day to recharge the internal thermal mass. A refrigerator that starts the cycle at 42°F (6°C) will hold safe temperature for another 2–3 hours after the generator shuts off.
Charge phones, power stations, and medical device batteries during the run window.
Rest the generator 2–4 hours between extended runs. Most portable generators are rated for 8–12 hours of continuous operation; exceeding that without cool-down shortens engine life.
Calculate fuel on hand against expected outage duration. A typical 3,500W generator consumes 0.5–0.7 gallons (1.9–2.6 L) of gasoline per hour at 50% load. Twenty gallons (76 L) of treated fuel provides roughly 30–40 hours of intermittent operation.

For full fuel storage and generator maintenance guidance, see fuel storage and generators.

Heating and cooling decisions for night two

The second night is typically harder than the first — indoor temperatures have drifted further from the thermostat setpoint, and fatigue reduces judgment. Plan for it:

Cold weather (heating outage): Consolidate the household into a single interior room. A room that the household occupies together — with body heat, sealed gaps under the door with towels, and heavy window coverings — retains warmth significantly longer than trying to heat the whole house. Per shelter insulation guidance, a well-insulated interior room in a modern house will drop only 1–2°F (0.5–1°C) per hour even in moderate cold, compared to an entire house losing 3–5°F (1.5–3°C) per hour. Sleeping bags rated to the outdoor ambient temperature are your backup if the room cools too much.

Hot weather (cooling outage): Move to the lowest floor (basements run 5–10°F / 3–6°C cooler than upper floors) during peak heat hours. Hang wet towels over open windows — evaporative cooling reduces apparent temperature significantly in low-humidity environments. If outdoor temperature drops below indoor temperature after sundown, open windows to ventilate. Identify your nearest public cooling shelter (public library, community center, shopping mall) before you need it.

Day 3 (hours 48–72): Escalation decisions

By 72 hours, the outage is no longer an inconvenience — it is an operational situation requiring deliberate decisions.

Evaluate evacuation

If the utility or news is reporting restoration in 4+ days, the rational question is whether staying in place is the right choice. Factors to weigh:

Factor	Stay	Evacuate
Household has elderly, infants, or medically dependent members	Capable of managing in-place?	Increasingly difficult after day 2
Fuel and food supply	7+ days available	Less than 3 days remaining
Seasonal temperature extremes	Indoor temp holding safe range	Indoor temp dangerous within 12 hr
Medication cold-chain	Maintained with cooler/ice	Running out of ice, meds at risk
Utility restoration estimate	1–3 days	4+ days

If evacuating: call ahead to friends, family, or a hotel before departing. Confirm destination has power. Carry your medication log, identification documents, and enough food and water for 24 hours in transit. See evacuation planning for the full route and documentation checklist.

Switch from preserving to rationing

If you are staying, the discipline shifts from preserving what you have to rationing what remains:

Fuel: Calculate generator fuel on hand. Reduce daily run time if the outage is extending. Prioritize medical devices over food preservation over lighting.
Food: Move to shelf-stable foods — no-cook items that need no refrigeration and no cooking fuel. Per FEMA Ready.gov 72-hour kit targets, aim for 2,000+ kcal per person per day from pantry items (canned goods, peanut butter, crackers, dried fruit, nuts).
Water: If you have not already, begin tracking consumption. 1 gallon (3.8 L) per person per day is the FEMA minimum; 2 gallons (7.6 L) is the realistic target including cooking and basic hygiene.

Document losses before discarding

Before throwing out spoiled food:

Photograph the entire freezer and refrigerator contents — open shelves, visible items, quantity.
Note timestamps and the last verified temperature in your log.
Check your homeowner's or renter's insurance policy for food-loss coverage. Most standard policies include a sublimit; your documentation is the claim.
Contact your utility about customer assistance programs — many US utilities provide credit or reimbursement after outages that exceed a threshold duration.

Pre-event preparation that determines outcome

The 72-hour response is determined almost entirely by what you did before the outage. The decisions are faster, the losses are smaller, and the stress is lower when the groundwork is in place.

Critical-load inventory

Before the next outage, identify your critical electrical loads and their daily watt-hour requirement:

Load	Typical draw	Daily Wh estimate
Full-size refrigerator	100–200 W cycling	1,000–1,500 Wh/day
Chest freezer	30–100 W cycling	300–800 Wh/day
CPAP (without humidifier)	30–60 W	240–480 Wh/night
Phone charging (4 phones)	15–20 W combined	60–80 Wh/day
LED lighting (4 bulbs)	10–40 W combined	80–320 Wh/day
Well pump (1/2 HP)	750–1,000 W surge	200–500 Wh/day

Sum the loads that matter most to your household. A typical family of four with a refrigerator, some lighting, and phone charging needs 1,500–2,500 Wh per day of backup capacity to maintain essentials. A portable power station in the 1,500–2,000 Wh range with a 200 W solar panel can bridge a 24–72 hour outage for those loads without any generator fuel. See portable power stations for sizing specifics.

Pre-event checklist

Run this checklist before major storm season (typically late spring and early fall in most US regions):

Field note

Fill any unused freezer space with 1-gallon (3.8 L) water jugs before storm season. Frozen water jugs act as thermal mass, extending the freezer's hold time from 48 hours toward 60+ hours. When the outage ends — or if the outage extends far enough that you need to ration — those jugs become an additional potable water supply. Two birds, one frozen jug.

The quality of your first hour in an outage is almost entirely a product of what you did in the weeks before it. With the right pre-event setup, a 72-hour outage is an inconvenient camping trip. Without it, the same event can mean significant food losses, medication emergencies, and real health risk. Set up portable power station backup capacity and generator fueling protocols before you need them — the cost in time and money before the outage is a fraction of the cost during it.