I had some wierdness with dash instruments and others have complained too. It is not impossible the engine didn't overheat but the gauge was acting up as well as other electrical components.
From the sounds of it, the starter is not rotating andengine not turning over. I resolved my problems by removing fuses, and cleaning the ends where they clip into the holder. None were burned out, but the surfaces were slightly corroded and continuity was intrermittent.
The only good thing that could be said was the fix was cheap enough your friend can attempt this without any exotic tools.
I wish him luck! Jim Northrup, Sr.