Recently,my HP has started locking up when flying in FS9. There is no method to its madness. It will freeze,and keep looping the sound. I have to press the power button on the PC to get it to do anything. Could it be over heating?
If your CPU were getting about about 65C, I might start to get a little concerned.
As for GPU, it depends entirely on which one you have. Most nVidia GPUs can safely operate at 105C, but research is needed before a blanket statement can be issued.
Post a screenshot of the Speedfan windows and someone will take a look.