How Cold Temperatures Affect Viruses in Your Refrigerator and Freezer

Most viruses survive refrigerator temperatures, but freezing slows their spread

Refrigerator and freezer temperatures do not kill most viruses. A standard refrigerator at 40°F (4°C) actually preserves many viruses in food and on surfaces—the cold slows their activity but leaves them viable. Freezing at 0°F (−18°C) or below is even more protective: viruses enter a dormant state and can remain infectious for months or years, depending on the virus and what they are frozen in.

This matters for food safety because viruses like norovirus, hepatitis A, and rotavirus can contaminate raw foods and survive your refrigerator's temperature. Thawing food at room temperature reactivates them. Cooking to the proper internal temperature is what actually destroys viruses—cold storage alone does not.

The reason cold preserves viruses is straightforward biology. Viruses are not alive in the way bacteria are; they do not metabolize or reproduce on their own. Cold does not starve them or poison them. It simply pauses their activity. When conditions warm up again, they resume their infectious state.

Key Takeaways

• Refrigerator temperatures (40°F) preserve most food-borne viruses rather than kill them, so contaminated food remains a risk throughout storage.
• Freezing (0°F or below) keeps viruses dormant and viable for extended periods, sometimes for years depending on the virus type.
• Thawing food at room temperature reactivates viruses, which is why safe thawing methods (refrigerator or cold water) matter more than freezing itself.
• Cooking food to the correct internal temperature is the only reliable way to destroy viruses; cold storage cannot do this.
• Viruses on refrigerator surfaces survive cold just as they do in food, so regular cleaning with soap and water or disinfectant remains necessary.

Why refrigeration does not kill viruses

Viruses lack the cellular machinery that bacteria use to survive. They cannot eat, grow, or repair damage on their own. Instead, they hijack a host cell's machinery to reproduce. This dependence on living cells is what makes them vulnerable to heat and certain chemicals—but not to cold.

When temperature drops, viral activity slows dramatically. The chemical reactions that allow a virus to infect a cell happen more slowly. But the virus itself remains intact and ready to infect again once it warms up. Think of it as putting the virus into hibernation rather than killing it.

This is why viruses like norovirus and hepatitis A can contaminate shellfish or leafy greens, survive your refrigerator for days or weeks, and still cause illness if the food is eaten raw or undercooked. The cold does not reduce the risk—it just delays the problem.

How freezing affects viral survival

Freezing is more effective at preserving viruses than refrigeration, which might sound counterintuitive. At freezer temperatures, viral particles enter a state of near-complete dormancy. Ice crystals form around them, but the virus itself does not break down. Depending on the virus and the food matrix (whether it is in fat, protein, or water), viruses can remain infectious for months or even years in a freezer.

Hepatitis A virus, for example, can survive freezing for extended periods. Norovirus also remains viable through freezing. This is important to know because it means frozen food contaminated before freezing stays contaminated after thawing. Freezing buys time—it stops the clock on spoilage—but it does not clean the food.

The protective effect of freezing is so strong that laboratories and vaccine manufacturers actually use freezing to preserve viruses for research and production. This underscores that cold is a preservation method, not a disinfection method.

Thawing and reactivation of viruses

When frozen food thaws, viruses reactivate. This is why the method you use to thaw matters. Thawing at room temperature on a counter allows viruses to become active again while the food is still in the danger zone (40°F to 140°F), the temperature range where bacteria and viruses multiply fastest. Even though viruses do not reproduce outside a living host, they become infectious again and ready to cause illness if eaten.

Safe thawing methods—in the refrigerator or in cold water—keep food cold enough that viruses remain dormant during the thaw. Thawing in the refrigerator takes longer but is the safest option. Cold-water thawing (changing the water every 30 minutes) is faster and still keeps viruses from becoming active.

Cooking is the only step that actually destroys viruses. Proper internal temperatures vary by food type: poultry reaches safety at 165°F (74°C), ground meats at 160°F (71°C), and whole cuts of beef or pork at 145°F (63°C) for medium. A food thermometer is the only reliable way to confirm these temperatures.

Viruses on refrigerator surfaces

Viruses do not just survive in food—they also survive on refrigerator surfaces. A virus left on a shelf, handle, or drawer at refrigerator temperature can remain infectious for hours or days, depending on the virus and the surface material. Stainless steel, plastic, and glass all harbor viruses in the cold.

This is why cleaning your refrigerator regularly matters, especially after storing raw meat, poultry, or seafood. Wipe down shelves, drawers, and handles with a cloth dampened in warm soapy water, then follow with a disinfectant spray or a solution of one part bleach to ten parts water. Let the disinfectant sit for the time recommended on the label—usually one to ten minutes—before wiping dry.

Pay special attention to areas where raw meat drips or where you have stored foods that were recalled for viral contamination. Cross-contamination from a contaminated surface to ready-to-eat foods (like deli meat or cheese) is a real risk in a cold refrigerator.

Which viruses are most common in food

Norovirus is the leading cause of viral foodborne illness in the United States. It spreads through contaminated food and water and survives refrigeration and freezing. Symptoms appear within 24 to 48 hours and include vomiting, diarrhea, and stomach cramps. Norovirus outbreaks are common in settings like schools, cruise ships, and restaurants.

Hepatitis A virus also survives cold storage and can contaminate shellfish, produce, and ready-to-eat foods. It causes liver inflammation and can take weeks to resolve. Unlike norovirus, hepatitis A can be prevented by vaccination.

Rotavirus primarily affects young children and also survives refrigeration. Enterovirus and sapovirus are less common but follow the same pattern: cold storage preserves them, and cooking destroys them.

Storage practices that reduce viral risk

Store raw meat, poultry, and seafood on the lowest shelf of your refrigerator, in a sealed container or on a plate, so drips cannot reach other foods. Keep raw and ready-to-eat foods physically separated. Use separate cutting boards for raw meat and produce—viruses on a cutting board used for raw chicken can transfer to lettuce or tomatoes.

Wash your hands with soap and warm water for at least 20 seconds after handling raw meat or poultry. Wash produce under running water, even if you plan to peel it. Do not rely on your refrigerator temperature to make these foods safe; it will not.

Label leftovers with the date and use them within three to four days. Viruses can still be present after this time, but the risk of bacterial growth increases significantly. When in doubt, throw it out.

Frequently Asked Questions

Can I get sick from eating food that was thawed and refrozen?

Yes, if the food was contaminated before freezing. Thawing and refreezing does not remove viruses—it just puts them back into dormancy. The virus remains in the food. If the food was thawed at room temperature, viruses had time to reactivate, and refreezing does not deactivate them again. Thaw only what you plan to use.

Does my refrigerator's ice maker produce clean ice?

Ice made from tap water is as safe as the water supply it came from. If your tap water is safe to drink, ice made from it is safe. However, if your ice maker has not been cleaned in months, bacteria and mold can grow on the interior surfaces. Clean the ice maker according to your refrigerator manual, usually by running a cleaning cycle or wiping interior surfaces with a damp cloth.

How long can viruses survive on a refrigerator handle?

It depends on the virus and the material, but most food-borne viruses survive on stainless steel or plastic handles for several hours to a few days in cold conditions. Norovirus can persist longer than some others. Wipe handles with a disinfectant weekly, or more often if someone in your household is sick.

Will freezing kill bacteria or viruses in food?

No. Freezing preserves both bacteria and viruses. It does not reduce their numbers or make them less infectious. Cooking is the only method that reliably destroys both. Freezing is useful for extending storage time, but it does not make unsafe food safe.

Is it safe to eat food that thawed during a power outage?

It depends on how long it thawed and the type of food. If the food stayed below 40°F, it is generally safe. If it rose above 40°F for more than two hours (or one hour if the room was above 90°F), discard it. Viruses can reactivate during thawing, so when in doubt, throw it out. A food thermometer can help you check the actual temperature.