CPU temp never gets above 52 C and my GPU never gets above 72 C. Not a heat issue. System temp is usually stable at about 43 C.
Good suggestion though.
Had another player check his temps on gpu it reported never going over 50, turns out his video card fan had died
if your fps is dropping after an initial cold start this is another sign of heat as well.
Just thinking from when you said you had a massive increase in fps the other day