Offtopic, but if you are getting thermal shutdowns, and you aren't afraid of taking your computer apart, look for dust buildup on the coolers. They are the typical cause of overheating, I had to take my computer completely apart and clean every part a couple months ago due to a similar issue.
If you are nervous about cleaning your computer, just buy a can of air. You can get it at most hardware stores. Just open up the shell of your computer and use the can to blow out the dust and debris. Works on keyboards as well. Has a pretty small nozzle and the air is pretty forceful so it works very well.
