A stated .. list full PC specs including make/model of your PSU, GPU and other components, case you are using as well as type of cooling on your CPU/GPU
Generic things to check/do
Make sure you have good air flow in your case
Make sure you are running separate power cables to each power input on your GPU
You can try adjusting your fan curve on your GPU to ramp up more when gaming
Make sure you have latest chipset drivers installed for your setup from either Intel or AMD's websites
You can run the program called DDU .. remove all things AMD, and Nvidia if that was a past GPU you ran on this Windows install .. reboot .. and THEN install latest GPU drivers from AMD's website
Make sure your Windows install is up to date