To keep your refrigerator running efficiently it should be set at 37-40 degrees Fahrenheit. Your freezer should be set at 0 degrees Fahrenheit. If your refrigerator does not have a built in thermostat your should put one in to make sure it is working properly. Never put hot food in the refrigerator, always let it reach room temperature. Lastly if there is ever a power outage open the door as little as possible.