When the power goes out, your refrigerator and freezer will only stay cold for so long. According to the American Red Cross, an unopened refrigerator will keep food cold for four hours. After this, temperatures will begin to rise to unsafe levels.
A full, unopened freezer will keep food frozen for 48 hours; a half-full freezer will stay frozen for 24 hours.
During an outage, it’s helpful to have a food thermometer on hand. You can use it to see which foods are safe to eat by checking the temperature of the refrigerator. Throw out any food that has been exposed to 40-degree temperatures for two hours or more.
You can extend the cooling life of your refrigerator by preparing beforehand. Keep one or two gallons of water in the freezer; not only will this make your freezer more efficient when the power is on, but when it goes off, you can transfer these frozen jugs to the refrigerator to keep food cold longer.
If you have a large cooler, you can cool foods even more efficiently by transferring them to the cooler. Use ice or your frozen water jugs to keep the food cold.