The recommended temperature for a freezer is at or below 0°F (-18°C) . This temperature is cold enough to keep food frozen and preserve it until it is ready to be cooked or reheated. It is important to keep perishable items cold, but not so cold that vegetables lose their freshness. The ideal temperature for a refrigerator is between 35 and 38 degrees Fahrenheit (1.6°C and 3.3°C) in the main part of the fridge, with the optimal temperature at 37 degrees Fahrenheit (2.8°C) . The refrigerator temperature should always remain under 40 degrees Fahrenheit (4.4°C) in all sections. It is recommended to place an appliance thermometer in the freezer to make sure the temperature stays constant and to check it regularly. If the power goes out, it is important to keep the freezer door closed as much as possible. When the door stays closed, a freezer can keep food at a safe temperature for around 48 hours.