Why does our Magic Chef refrigerator get hot?

Approximately one year ago, we were told our Magic Chev refrigerator was heating up because it was too close to the wall, so we moved it about six inches from the wall, and it stopped heating up. Recently, it is heating up again even though it is not close to the wall. It is a small frig with the freezer on top. It heats up on the outside side and door of the freezer section. We do not have an owners manuel and I think it's about seven to eight years old.