temperature outside is lower than 40 degrees appliance thermometerExternal refrigerator thermometer FDA advises appliance thermometer maintained at cold temperatures Refrigerator Thermometers: Cold Facts about Food Safety set to 0 F far above food safety guidelines US Food and Drug Administration Per the FDA safe operating temperature recommends a temperature of <40°F Food and Drug Administration According to the FDA zero degrees Fahrenheit necessary to save food at the proper temperature Food and Drug Administration misuse can greatly increase food waste set by the FDA FDA suggests FDA double every 20 minutes 40 F or lower cold temperatures minimally below 40° FDA goes up thermometer Refrigerator Thermometers: Cold Facts about Food Safety aumenta recommends a temperature of <40°F 40 degrees F or lower Don’t pack your fridge tight safely cold above 40°F 0 degrees F