I gave it a bit more thought on the drive home. If your computer is running that hot, some part of the heat management most likely has failed. i.e., fan has died, heatsink has somehow come loose. The probable reason that you cannot run your programs is that the processor has detected the excessive heat and is slowing itself down to prevent self-destruction.
If the high temperature continues, shut it down immediately and take it for service (assuming it's under warranty).