If a large amount of food has recently been stored, or if the doors are opened frequently or for long periods of time, your refrigerator will not cool as quickly. Make sure the controls are set to the recommended setting (marked on the dial), and that nothing is blocking the internal air vents.
If the room temperature is unusually high, try adjusting the refrigerator to a cooler setting. Wait 24 hours for it to take effect.
Try vacuuming the condenser coils behind the front kick plate of the fridge. If this doesn't work, manually defrost the freezer.
If the unit cools normally after manual defrost, replace the automatic defrost assembly, located above and behind the refrigerator side.
When to Call a Pro
If your refrigerator still doesn't cool after manual defrost, contact a repair technician to check your coolant levels and compressor. If you are unfamiliar with electrical repair or if your unit is under warranty, always call a professional first.