Limiting FPS to something reasonable should help. The menu is a complexish scene but with good hardware it'll pull hundreds of frames a second if unlimited. And that will generate heat.

I had my fans ramp up to max every time I went sailing and the temps jumped way up. The cause was the decrease in what the GPU needed to render so it just pulled 400-500+ fps on the open sea. Once I put a limiter to it everything was fine.