What to Do When the Power Goes Out for Days

The food-safety rule most people remember is the one that rarely bites them: a closed refrigerator buys you about four hours. The one that actually causes illness is quieter — food that thawed and spent two hours above 40°F is unsafe to eat, and it will give you no warning. It won’t smell wrong. It won’t look wrong. The decision is made entirely by temperature and time, and the clock starts running the moment you can’t hold it.

That same logic governs a multi-day outage from top to bottom. The dangers that send people to the hospital — spoiled food, carbon monoxide, heat stroke — are all invisible. What follows is the guide for navigating them.

Two Clocks, Not One: What Happens to Your Food

There are two separate timers in play, and conflating them is the most common mistake. They answer different questions.

The first is the hold time: an unopened refrigerator will keep food in a safe temperature range for about four hours. That figure assumes the fridge started at the right temperature, the door stays closed, and the room isn’t unusually hot. Every time you open the door, you spend some of that buffer.

The second is the discard threshold: once food has been above 40°F for two hours or more, perishables — meat, dairy, eggs, leftovers — should be thrown out. These two numbers aren’t contradictory; they’re sequential. The four-hour window tells you when the temperature likely crossed 40°F. The two-hour rule tells you what happens after it does.

The thing that gets people in trouble is checking on the fridge, finding that the food still looks and smells fine, and deciding it’s okay. It isn’t, necessarily. Foodborne pathogens don’t announce themselves. The rule is temperature and time, not your nose.

The freezer buys you more time — but how much depends heavily on how full it is:

These figures come from USDA-derived guidance repeated across public health agencies — treat them as solid planning baselines, not guarantees. A well-insulated chest freezer in a cool basement will outperform a side-by-side unit in a warm kitchen. The half-full number especially is less forgiving than most people expect, because the frozen mass itself is what holds the cold. Air doesn’t.

The refreeze decision is where illness actually slips in. People check the freezer, find meat that’s cold but soft, and figure it can go back in. The test isn’t how it feels — it’s whether ice crystals are still present throughout, indicating the food stayed cold enough. If those are gone, the food sat in the danger zone long enough to matter, and refreezing it doesn’t undo that.

The Invisible Killer: Generator and Combustion Safety

Carbon monoxide has no color, no smell, and no taste. It kills people in outages every year because they run a generator, grill, or kerosene heater somewhere they believe is “close enough” to outside — an open garage, just inside a cracked window, a porch with three walls. None of those are safe.

The rules here are not suggestions:

• Run any combustion device — generator, gas grill, charcoal, kerosene heater — outdoors only, at least 20 feet from any window, door, or vent.
• An attached garage is not “outside,” even with the door fully open. CO drifts in and accumulates.
• Don’t run a car engine in the garage to charge devices. Same problem.
• Let a generator cool before refueling — spilled fuel on a hot engine ignites.
• Never backfeed a generator into your home’s wiring through an outlet. It endangers utility workers on the line and can damage your equipment.

The safeguard the sources underplay: a battery-powered carbon monoxide alarm. If CO does enter the house, you will not detect it yourself in time. A CO detector — one that runs on batteries, since the grid is down — is the only warning you’ll get. It belongs on your emergency prep list alongside the flashlight and the radio.

What to Do the Moment the Power Goes Out

Before anything else, figure out whether this is your problem or the grid’s. Check your breaker box. Ask a neighbor if their power is out too. If it’s just you, the fix may be a tripped breaker. If it’s the neighborhood, report it to your utility — outages that aren’t reported take longer to prioritize.

Then take two minutes to reduce the damage when power returns:

• Turn off and unplug computers, TVs, and anything sensitive. When the grid comes back, it often comes back with a surge, and that surge can damage electronics.
• Switch off the stove, space heaters, and any appliance you were actively using. A stove left in the “on” position when the power failed will reactivate, unattended, when it returns.
• Leave one lamp switched on so you’ll know the moment power is restored.

These steps take less than five minutes and prevent the secondary damage — the appliance fire, the blown equipment — that turns an inconvenient outage into a costly one.

Light, Supplies, and Fuel: Getting the Basics Right

Lighting: Use flashlights or battery-powered lanterns. Not candles — candles are a fire risk that compounds in the dark, especially with children, pets, or anyone moving around a house they can’t fully see. In summer, they also add heat to a space that’s already warming up. One thing worth knowing about those battery-backup light bulbs: the “6 hours” figure on the packaging is a manufacturer spec under ideal conditions, not a tested runtime. Treat it as a nominal ceiling, stock more batteries than you think you need, and don’t rely on a single battery bulb as your only source of light through a multi-day outage.

Fuel: Keep your gas tank at least half full as a standing habit. Fuel pumps run on electricity. In a widespread outage, many stations will be dark for days, and the ones that aren’t will have lines. If the tank is already half full when the outage hits, you have range. If it’s on empty, you’re stuck.

Water and food: The standard preparedness planning targets are one gallon of water per person per day, with a 3-day supply for potential evacuation and a 2-week supply at home for sheltering in place. Stock non-perishable, easy-to-prepare food on the same horizon. Keep at least a 7-day supply of essential medications — pharmacies may not be open or reachable. One caveat on the water figure: one gallon per day is drinking plus minimal sanitation. Hot weather, medical needs, infants, or pets all push real consumption higher.

The Question That Determines Everything: Can You Stay?

For a one-day outage, most households can manage in place. For a multi-day outage, the critical question isn’t inconvenience — it’s temperature.

Extreme heat and extreme cold are what actually injure and kill people in prolonged outages, not the darkness and the spoiled food. An elderly person, someone with a serious illness, a very young child: these are the household members who can deteriorate quickly in an unheated house in winter or an uncooled house in a heat wave. If the outage is expected to run several days and you have anyone in that category under your roof, the decision to relocate to a shelter, a friend’s house, or a family member’s home should be made early — not after the situation has become dangerous.

A few other things that matter for extended outages:

• Know how to manually release your electric garage door — it’s usually a red cord hanging from the rail. You may need to leave quickly without grid power.
• Keep a battery-powered or hand-crank radio. It’s how you’ll receive emergency updates and utility restoration timelines when your phone is dead and the internet is down.
• If you’re cooking, do it outdoors on a grill or camp stove — or use a fireplace. No indoor combustion, ever.
• Check on neighbors who are elderly, ill, or living alone. The temperature threat applies to them even if you can’t see it from the outside.

The One Rule That Covers All of It

Every danger in a multi-day outage shares the same structure: the threat is invisible, the warning sign is absent, and by the time something looks wrong it may already be too late. Spoiled food doesn’t announce itself. Carbon monoxide doesn’t either. Heat illness can progress faster than it feels like it’s progressing. The discipline that keeps people safe is making decisions on facts — temperature and time, 20 feet and outdoors, half a tank before the outage — not on sensory reassurance. When you can’t see or smell the danger, the rule is the only instrument you have.