Leo K. O‘Drudy III is a writer with the Food Safety and Inspection Service at the U.S. Department of Agriculture.

The hurricane season of late summer and early fall is behind us, so it may be tempting to believe that all weather-related threats to food safety are behind us as well. However, winter storms can cause power outages that disable refrigerators and freezers, too. Foodborne illness is bad for everyone, but if you have cancer you have to be especially careful to avoid getting sick from spoiled foods.

1. 1. Keep those doors closed.

   If you do lose power during a winter storm, keep the refrigerator and freezer doors closed as much as possible. A refrigerator will keep food cold for about 4 hours if the door is kept closed. A full freezer will hold its temperature for about 48 hours. A half-full freezer will stay at a sufficient cold temperature for 24 hours.

2. 2. Winter weather pros and cons.

   If you do lose power in the winter, DO NOT try to use the cold winter weather as an outdoor refrigerator or freezer.

   Even when there is still snow and ice on the ground, outside temperatures can vary. This can cause chilled food to enter the “danger zone,” between 40°F (4.5°C) and 140°F (60°C). At those temperatures, frozen food will begin thawing, but it won’t be hot enough to kill bacteria. Moreover, food left outdoors can be exposed to animals and other dirty, unsanitary conditions. 

   However, there is one way the winter conditions can be helpful. Refrigerators and freezers are so well insulated that you can put ice in them to keep foods cold, just like an old-fashioned “icebox” that uses ice instead of electricity to keep food chilled. Coolers that you use for picnics, camping, or other outdoor activities can also be filled with ice and used to keep foods safe. If the weather is cold enough, you can make fresh ice by filling buckets or cans with water and leaving them outside to freeze. Use this ice to help keep food cold in the freezer, refrigerator, or coolers.

   Remember to place meat and poultry to one side of the freezer or on a tray. If the food starts to thaw, liquid may start to flow from them and spoil other foods. Separating meat and poultry beforehand can help prevent cross-contamination.

3. 3. When power returns.

   Once the power comes back on, it’s time to carefully examine everything and throw away anything that may be unsafe. 

   First, check the temperature inside of your refrigerator and freezer. If any perishable food, such as meat, poultry, seafood, eggs, or leftovers, has been above 40°F (4.5°C) for 2 hours or more, get rid of it.

   Next, check each food item separately. If there is food in your freezer that is partially or completely thawed, it can be safely refrozen if it still contains ice crystals or is 40°F (4.5°C) or below. Throw out any food that has an unusual odor, color, or texture or if it feels warm to the touch. Never taste a food to decide if it's safe. When in doubt, throw it out.

Need more food safety information? Call the USDA Meat & Poultry Hotline at 1-888-MPHOTLINE (1-888-674-6854). You can also submit a question or chat live with a USDA food safety specialist at AskUSDA, Monday through Friday, in English or Spanish.