I would boot into BIOS settings and record the CPU temp that is there and shut down the PC.
I would remove the CPU cooler, blow it out with compressed air, clean the CPU cap and cooler contact metal surface with isopropl alcohol and a coffee filter, then apply a thin vertical line of thermal paste on the CPU cap and put the cooler back on. Then I'd go back into BIOS settings and see if the temperature has improved. If not, I would shut the PC down for 10 mins and remove the side panel of the case, start back up and see if that helps.
If that doesn't help I'd replace the cooler although those kinds of temps temps should never happen even on a stock cooler unless you are overclocking.