Although overheating can be a sign of other issues, such as your tablet being overworked or battery problems, the case can be the culprit as well. This is especially true of thick plastic tablet cases. If you notice that your device overheats while in its case, try removing it and allowing it to cool off before replacing it. You might also want to use your device without the case for a while to discern whether the problem is the case or your tablet.