Have you checked your owners manual under "trouble shooting"?
If you do not have the owners manual, you might be able to get one on line by typing the year, type and model of your fridge and add, owners manual, then click send.
If it is a frost free take the kick plate off the bottom and make sure that the area behind is not blocked with fluff etc as thhis prevents the intake of air required for correct operation. I have a Amana and had this very problem only a few weeks ago.