How long does food last in the fridge without power?

Here’s your guide to determining which food items to keep or toss after you lose power:

Meat, poultry, fish and eggs should be kept refrigerated at or below 40 degrees Fahrenheit and frozen food at or below zero degrees. When the power goes out, the refrigerator will keep food safely cold for about four hours if unopened, according to the USDA. A full freezer will maintain the temperature for about 48 hours (24 hours if half full) if the door is not opened.

Most recommendations on whether food is still safe to use are based on the temperature inside the refrigerator using a digital, dial or other type of thermometer.

But what if you’re not at home? How could you know if items in your freezer thawed and then froze again when power was restored?

Freeze a small bowl of water and put a penny on top. If you return and the penny is at the bottom of the bowl or inside of the ice, you’ll know if other things in the freezer thawed too.