galaxy tab 3 getts warm while on but not being used for 10 min. approx

A

AC Question

I have a Samsung galaxy tab 3 had for 2 months. It got hot once while charging, heat felt through case on hard surface sitting on. Now when on but not being used for about 5 - 10 min. it gets warm especially on the left side top and bottom. Software not performing correctly. when used for game it will change from game screen then to home page and back and forth, when logging on the screen goes black but responds when on/off button mashed.