When refrigerators and freezers suffer a loss of electrical power, the refrigerated and frozen foods inside can become susceptible to foodborne contaminants in just a few hours.

Severe weather events such as blizzards, thunderstorms, and tornadoes can bring down power lines in a neighborhood. When the power goes out, the clock starts ticking on the viability of meats, seafood, ice cream, cut produce and even leftover pizza.

According to the USDA, bacteria such as E. coli, Salmonella, and Campylobacter can grow within minutes of food entering the “Danger Zone” – the range of temperatures between 40°F and 140°F.

A refrigerator in good working order can maintain its temperature for about four hours; a full, reliable deep freezer can keep food frozen as long as 48 hours.

If you have nearby friends and neighbors that have extra space in their freezer, consolidating frozen foods is a great strategy. A full freezer will maintain its temperature longer than a freezer that’s only half full.

If you know a winter storm or blizzard is on the way, consider moving as much as possible from the refrigerator to the freezer. Leftover pot roast, tuna casserole, and plastic bottles of fruit juice will keep these foods in a colder environment and helps fill empty spaces in the freezer. You can also use water bottles, plastic gallon jugs of water, plastic storage containers filled with water. Just get them frozen before the power goes out. If you have a source for dry ice, consider adding a few blocks to your freezer. Dry ice can extend your safe zone by several hours.

As much as you can keep the doors closed. Don’t open them to peek in and check to see what the temperature is – just leave them closed. Avoid that temptation.

Refrigerator and freezer-rated thermometers are also a good permanent addition to your appliances. They’re inexpensive and will give you a reading the first time you open the appliance, after the power has been restored, and are important to use anytime.

After that, the question is simple: Keep it or toss it? Foods that are most vulnerable include meats, seafood, dairy and ice cream while those that are a bit more stable are whole fruits and vegetables, condiments and hard block cheese.

When checking the freezer, ice can be a good indicator. If an item is still frozen solid, or if you can still feel ice crystals, that’s a good thing. Whatever you do, don’t taste something and think, ‘Well, if it tastes OK, it’s still good.’ Bacteria doesn’t always reveal itself that way. The oft-repeated adage holds true: When in doubt, throw it out.