It's also a simple matter to add a fan, which helps enormously with the heat issue. Novak makes a fan that's the right size (you can find that size from other sources as well) that can be mounted directly on top of the esc by running some screws into the heatsink. As mentioned above there are other issues at work here with your specific problem, but the fan is a cheap 'in general' cooling helper.
Well if it seems to be real, it's illusion
For every moment of truth, there's confusion in life...