What Are the Ideal Temperatures for a Refrigerator & a Freezer?

We don't think much about the exact temperature of the inside of the refrigerator as we rifle through its contents looking for that ideal snack. But if the interior of the appliance isn't consistently within a few degrees of the right refrigerator temperature, it can cause spoiled food at best and illness at worst.

A refrigerator or freezer that's too cold may not cause food-borne illnesses, but it can put a big dent in the grocery budget as fresh food becomes extra crisp with ice crystals along leaf edges or hard-boiled eggs that are more frozen than edible.

The refrigerator's entire purpose is to keep food at a safe temperature. It's not always easy to know if the fridge is humming along at the right temperature. You may not hear knocks or pings.

The main reason a refrigerator and freezer need to be at the correct temperature consistently is due to a tiny bit of bacteria that can cause a big issue. Microorganisms can create a few hours of uncomfortable symptoms, such as nausea and mild diarrhea. It can also create serious problems that require hospitalization, particularly for young children, the elderly or those who have an underlying medical condition or weakened immune system.

The refrigerator's job is to slow down the growth of bacteria on fresh and package foods. Bacteria is a naturally occurring organic growth. It exists in soil, water and air, and therefore in the food that's grown in fresh earth or processed in a plant.

Given the right environment, nutrients and moisture, bacteria will flourish rather quickly and often go undetected to the naked eye or first whiff. Pathogenic bacteria flourish when the refrigerator temperature rises above 40 degrees Fahrenheit. Spoilage bacteria can grow on packaged and fresh foods in a refrigerator that has a low temperature.

Pathogenic bacteria flourish when the refrigerator temperature is in the danger zone, according to the United States Department of Agriculture. This type of bacteria sits silently on the lunch meat or clings unseen on the leftover macaroni or unwashed fresh fruit. A pathogenic bacteria isn't easy to see, taste or smell but will spread quickly over the surface of the food.

Spoilage bacteria will make the food taste off or bad but will often show up without making the food item look discolored or otherwise visually known. The quality of the food is affected, creating a bad taste or smell.

The lettuce may not throw out a warning signal with limp leaves outstretched in obvious distress. However, if the refrigerator isn't at the proper degree, it can lead to a shorter shelf life for fresh vegetables, fruits, cheeses and other foods that are affected by warmer temperatures.

The Federal Drug Administration recommends keeping the refrigerator between 37 and 40 degrees Fahrenheit. The freezer should be at 0 degrees Fahrenheit to keep bacteria from getting a grip on ground meat, soup bones, frozen vegetables or other items in cold storage.