33c is not really a problem. If you're not having instability problems at high FSB it likely not an issue at all. However, a small heatsink of the type typically used with TO-220 package transistors can be super glued to the top of the chip, and if you have airflow in the case, it should cool off a few degrees.
The BX chip is more important to cool, and I recommend removing the green heatsink, and putting a good thermal compound under it. I have seen some that had none, and others that had a little spot in the middle only. On my BF6 I have a Tennmax lasagna cooler on the chip and it helps stability at 145+ FSB.