According to the recipe from which this one is adapted, the spice level for this recipe is gauged as MEDIUM HOT; however, in my experience, it is slightly hotter than medium. (I'd rate it about a 6 or 6.5 on a 1-10 heat scale.)  For one test batch, I used two tablespoons of cayenne instead of three, and the results were (for my tastes) perfect - not painfully spicy, but with solid heat and a decided kick. (About a 4.5.)