Alice Henneman, MS, RDN, UNL Extension in Lancaster County
A gentleman had been traveling during a time when the electricity was off for several days in many homes in his community. However, when he returned home, his electricity was working and everything in his freezer was frozen solid.
He proceeded to eat some food from the freezer and got sick. What happened?
In this case, his electricity actually had been off for about a week, and then came back on. Everything in his freezer had thawed and been at unsafe temperatures for several days. As the food froze again when the electricity returned, he was unaware there were any food safety problems.
Here's a simple way to help detect this problem. Store an ice cube or two in a sealed plastic bag or small container in the freezer; a sealed bag/container is important so the ice cube doesn't evaporate and disappear. If the ice cube has melted down from its original shape, you'll know the power was off for an extended period of time.
A Consumer's Guide to Food Safety: Severe Storms and Hurricanes (Source: USDA Food Safety & Inspection Service)
Includes which foods are safe to keep if your power goes off.