Most households lose power 3–5 times per year. Most of those outages last under four hours. The 72-hour event — the one caused by an ice storm, a hurricane, a substation fire, or a grid cyberattack — is statistically rare but deeply inconvenient in ways that compound fast. The refrigerator holds food for 4 hours with the door shut. The toilet flushes from tank reserve until the tank empties. The phone charges from whatever was in the battery. The gap between "fine" and "actually a problem" is narrower than most people expect, and it closes faster.
The First 15 Minutes
The first quarter-hour sets the tone for everything that follows. Do not wait to see if power comes back — assume it will not. Fill every bathtub, every large pot, every clean trash can with tap water before municipal pressure drops (it usually drops within 6–12 hours of a widespread outage as pump stations lose power). That water is for flushing, washing, and — if needed — boiling for drinking . A standard bathtub holds 40–60 gallons. Fill it. Put a tarp over it to keep debris out. Then check on elderly neighbors within a 2-block radius — they are the most likely to need help and the least likely to ask.
Water: The 72-Hour Math
FEMA's standard is 1 gallon per person per day — that's drinking plus minimal sanitation. We recommend 1.5 gallons per person because cooking, basic hygiene, and one toilet flush per day per person eat that margin fast. A household of 4 needs 18 gallons stored for 72 hours. If your stored water is short, iodine tablets treat 1 quart per tablet in 30 minutes and cost roughly $8 for a 50-tablet bottle — that's 12.5 gallons of treatment capacity in your jacket pocket. Keep two bottles. Iodine has a 4-year shelf life; check the date every January.
- Fill all water containers immediately (minute 1–5)
Bathtubs, pots, buckets, clean trash cans — fill everything before municipal pressure drops. Target 1.5 gallons per person per day, minimum 18 gallons for a family of 4 over 72 hours. Tap off the bathtub spout, not the overflow drain.
- Freeze everything you can (minute 5–15)
Pack your freezer solid with water bottles and wet towels to extend cold mass. A full freezer holds temperature for 48 hours; a half-full one holds it for 24. Every empty space costs you food. Use any portable coolers to move the most perishable fridge items into the most-frozen part of the chest.
- Inventory and stage your food (hour 1)
Eat from the refrigerator first — it warms fastest. Dairy, meat, and leftovers go first; hard cheeses, condiments, and eggs last. Freezer food stays frozen well past 24 hours if unopened. Canned goods, dry rice, and peanut butter are your 48–72 hour food supply. Do not open the freezer before hour 24.
- Set up lighting and designate a command area (hour 1–2)
One LED lantern on the kitchen table is your central hub — conserve flashlight batteries by routing all activity through one lit zone at night. Hang a battery-powered string light in the bathroom so no one falls. Set all devices to airplane mode and screen-off at 10 seconds. A fully charged phone on airplane mode lasts 3–4 days in standby vs. 12–18 hours in active use.
- Establish a communications check-in schedule (hour 2)
Pick one out-of-state contact to be your household's single check-in point — local lines congest during regional outages, but long-distance often works. Text-only; voice calls eat battery 4x faster. Set two daily check-in windows: 8 AM and 6 PM. Write the contact's number on paper. A hand-crank or battery weather radio (NOAA) gives you official status updates without burning phone battery.
- Monitor temperature and medical needs (hours 4–12)
In summer heat, 95°F indoors becomes dangerous for infants, elderly, and anyone on diuretics or beta-blockers within 6–8 hours. Identify the coolest room (usually lowest floor, north-facing) and consolidate there. In winter cold, draft-block doors with towels and close off unused rooms. If anyone takes insulin or refrigerated medication, contact your utility's medical baseline program the moment power goes out — most have priority restoration lists.
- Test and document what failed (hour 72)
When power restores, write down exactly what you lacked and when. Was it a water gap at hour 6? A phone-dead situation at hour 48? Your after-action list drives your next prep purchase. One $40 item fixed at a time beats a $2,000 panic kit that sits sealed in a closet.
Food: What Actually Stays Edible
The USDA rule is unambiguous: discard any refrigerated meat, poultry, seafood, eggs, or cut produce that has been above 40°F for more than 2 hours. That is not a suggestion — it is a food-safety line. With a full, undisturbed refrigerator, you get about 4 hours of safe cold. Your 72-hour food plan should assume the fridge is empty by hour 8. What survives without refrigeration: hard salami, hard cheeses (sealed, uncut), peanut butter, crackers, trail mix, canned fish, canned beans, jerky, honey, and whole uncut fruits and vegetables. A jar of peanut butter has roughly 2,500 calories and needs no cooking, no refrigeration, and no stove. Per person, budget 2,000 calories per day — more if it's cold or you're doing physical work.
Power and Communications
A 20,000 mAh power bank charges a modern smartphone roughly 4–5 times. That is your communications lifeline for 72 hours if you manage it properly. Keep two banks; charge them to 100% every 3 months. A 100-watt folding solar panel and a 40Ah LiFePO4 battery ($180–$250 for both) is the single most useful power investment for urban/suburban blackouts — enough to run an LED lamp, charge phones, and power a small fan all day. It will not run a refrigerator or a sump pump. Do not try. For water-related gear, understand the difference: filtration removes particles and pathogens mechanically; purification kills or inactivates them chemically or with UV. That distinction changes which device you need for your water source . For urban tap water stored in clean containers, neither is needed. For questionable sources, use both in sequence.
What NOT to Waste Time On
Do not run a generator indoors or in an attached garage — carbon monoxide kills faster than hypothermia and gives almost no warning. Do not open your freezer repeatedly to check status — every opening costs you 30–45 minutes of cold retention. Do not use your gas range for heating; it works for cooking but produces combustion byproducts in an enclosed space. Do not spend hour 1 scrolling for outage updates — use that time to execute the water and food steps above. The utility company's outage map will not tell you anything actionable that a NOAA weather radio cannot tell you more reliably.
How much water do we actually need for 72 hours?
Plan for 1.5 gallons per person per day — that covers drinking, basic cooking, and minimal hygiene. For a family of four, that's 18 gallons. Store it in food-grade containers before an emergency; do not rely on having time to fill containers after an outage starts.
Can we run a generator inside the house if we leave a window open?
No. A window does not provide enough ventilation to safely dilute generator exhaust. Carbon monoxide accumulates even with windows cracked, and the odorless gas gives no warning before incapacitation. Run generators at least 20 feet from any door, window, or vent — outdoors only.
How long does food in the freezer last without power?
A full, undisturbed freezer holds food at safe temperatures for 48 hours. A half-full freezer holds for roughly 24 hours. The key is keeping it closed — every opening cuts that window significantly. Pack empty space with water bottles or wet towels before a storm to extend cold mass.
What is the single most useful prep purchase for a suburban blackout?
A 20,000 mAh power bank charged and ready — it costs under $40, fits in a drawer, and keeps phones alive for 4–5 full charge cycles. After that, a 100-watt folding solar panel paired with a small LiFePO4 battery ($180–250 total) handles multi-day phone charging and LED lighting without fuel logistics.
Should we shelter in place or leave during a 72-hour blackout?
Shelter in place for most 72-hour grid-down events unless local authorities issue an evacuation order or a medical need forces a move. Leaving during a regional blackout means navigating non-functional traffic signals, congested roads, and uncertain fuel availability — risks that outweigh the discomfort of staying home with water and food staged.