So many issues are caused by heat and suddenly shutting down is a fairly common one.
In the BIOS it might be possible ( but can also be a silly thing to do ) but the temp settings might be raised to give you a bit more lee-way. ( Just seen 100c - Okay then! forget about that )
In truth, you might be better off clearing all teh dust that you can from inside the PC, especially of course around the Fans etc
You might have a bit of luck with the CPU cooling too, even re-applying some thermal compound between the CPU and the heatsink.
Another thing that is often a good ideaa to do, is to NOT have your PC on a carpet. Put a piece of plywood perhaps and maybe this might help?
Im only looking for options that will be the cheapest things to try as the simple things are so often the solution. Never always but if they work, it saves you money that you then have for Dru... For other PC bits!!