There are two CUDA buttons on the logic board to the left of the diagnostic lights. Try pressing the lower one (just once), this resets the SMU which manages wattage and thermal conditions. Use the eraser tip of a pencil to do this. Now press the upper button to restart. If it's still hot examine the 24 capacitors on the logic board for swelling and/or corrosion and let us know your findings. Your CPU may have failed but it could also be the caps problem.