The ideal temperature range for a refrigerator is 35 to 38 F. Refrigerators often have warm zones and cool zones; 35 to 38 degrees ensures that food won't freeze and that bacteria doesn't have a warm environment to grow in. The freezer should be kept at 0 degrees or lower.
Refrigerators cool food for longevity and safety. At 32 degrees, items stored in the refrigerator freeze. Freezing can damage food, and it can make containers storing some liquids burst. Keeping the refrigerator at or about 35 degrees provides a bit of a cushion against freezing. At around 40 degrees, some types of bacteria, including some dangerous types, start growing much more quickly. A ceiling temperature of around 38 degrees provides a bit more protection against food poisoning.
The FDA recommends buying two appliance thermometers and placing them in both the refrigerator and the freezer to make sure your appliance is adjusted properly. Check them periodically to make sure your refrigerator to ensure they are cooling at optimal levels. One common reason for cooling problems is overloading. The cold air needs room to circulate around the food to keep it cool.
Keep your food safe by keeping it covered in the refrigerator, promptly cleaning up spills that can breed bacteria and putting food in the refrigerator as soon as possible.