Refrigerators and freezers must operate at precise temperatures for proper food preservation, maximum energy-efficiency and to keep them from working too hard and wearing out prematurely. The recommended levels are between 37 and 40 degrees for the refrigerator compartment and zero for the freezer section. There are individual dials and settings to control each one. Just putting a thermometer in the compartments won’t always give you an accurate reading due to door openings and fans that move air for moisture control and defrosting. To test the refrigerator side, place a thermometer in a glass of water in the center and leave it for 24 hours. For the freezer side, place the thermometer between two packages of frozen food, cover with plastic wrap and leave it for 24 hours. The next day check both and adjust accordingly, allowing another 24 hours for each adjustment until your “patient” is a perfect 37 to 40 and zero.