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Food is rarely what hurts people in an outage. Spoiled food is. Know the two clocks, then store meals you will actually eat.
By Walter Wolf · Updated November 2026
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In short
- A closed fridge keeps food safe for about 4 hours. A full freezer about 48 hours, a half-full one about 24.
- Perishable food above 4 °C (40 °F) for more than 2 hours gets thrown out. Never taste food to test it.
- Do not store food outside in the snow.
- Store meals that need no cooking and no fridge, that your family already eats.
- Do not forget a manual can opener.
The two clocks
The first clock is how long the appliance stays cold. The second is how long a food has been warm. They are not the same.
| Appliance, door kept shut | Stays cold for about |
|---|---|
| Refrigerator | 4 hours |
| Half-full freezer | 24 hours |
| Full freezer | 48 hours |
These are estimates, not guarantees. Every time the door opens, the time gets shorter. Write down when the power went out.
What to throw out
Once perishable food has been above 4 °C (40 °F) for more than two hours, throw it out. That includes meat, poultry, fish, eggs, milk, soft cheese, cooked leftovers and cut fruit.
- Never taste food to see if it is safe. Food can make you sick without smelling or looking wrong.
- Usually fine: hard cheese, butter, whole fresh fruit and vegetables, bread, peanut butter, jam, ketchup, mustard.
- Frozen food that still has ice crystals, or is as cold as a fridge, can be cooked or refrozen.
- A cheap fridge thermometer in each appliance takes the guessing out. See fridge thermometers on Amazon.
Being sick with no running water and no easy medical care is much worse than losing some groceries. When in doubt, throw it out.
A snowbank is not a refrigerator
It feels obvious to put the food outside when it is −20. Food safety agencies in both the US and Canada say not to. Sun warms dark packages even on a freezing day, temperatures swing, and animals get in. Outdoor cold is not a measured, steady temperature.
What does work: fill clean containers with water, freeze them outside, and move that ice into your fridge, freezer or a cooler. The cold comes in. The food stays in.
Eat in the right order
- Fridge food, in the first few hours, while it is still cold.
- Freezer food, as it thaws, if you have a safe way to cook it.
- Shelf food, last.
Cooking without a kitchen
Camp stoves and barbecues are for outdoors only. In deep cold, propane and butane canisters work poorly, and cooking outside costs a lot of body heat. So plan for meals that need no cooking at all, and treat hot food as a bonus.
What to store
Store food your household already eats, and rotate it through your normal meals.
- Ready to eat: canned fish, meat, beans, soup and fruit; peanut butter; crackers; granola and protein bars; dried fruit; nuts; cereal; shelf-stable milk.
- Just add water: instant oatmeal, instant noodles, freeze-dried meals. Remember they use your water.
- For special needs: baby formula, food for allergies or medical diets, pet food.
- The small things: a manual can opener, disposable plates and cutlery to save washing water, salt, sugar, coffee or tea.
Count in meals, not in cans. One person needs about three meals and roughly 2,000 calories a day, and more than that when the house is cold. For food that keeps for years, see the long-shelf-life food guide.
Sources
Official guidance this page was checked against. If your local authority says something different, follow them.