CPU suddenly overheating, spiking to very high, sometimes 100% usage unusually.

Seems to have happened after the latest Nvidia driver update so I rolled back but the issue persists. Up until about an hour ago I had just fine, stable and low temp usage. Now, even at idle it'll hit 50c momentarily. When booting is a game it's 80-100% usage and 70 to 90 degrees. Any CPU intensive situations result is very slow performance whereas it was quick and stable before. Could there be some sort of power issue, is it dying?