Is it sitting on a flat surface?
If you're not moving it much, I suggest you invest in a laptop stand.
I use one of these: NotePal ErgoStand Basic - Cooler Master
Which is amazing, I can play intense games and not experience any issues, whereas previously it would overheat even just being idle on a flat surface. I don't even use the fan component, just having it elevated with the mesh backing gives great airflow.