My wife and I finally took the plunge into the local taqueria scene. The place we visited has a reputation as one of the best taquerias in our area, and it seemed very authentic (as evidenced by the fact my wife and I were the only ones in the place speaking English). Anyway, we really enjoyed the experience, and I loved the flavor of the tacos I tried, especially the beef cheek one, but I had one reservation: the heat. I have a mid to low tolerance for spicy foods, and the building heat of the tacos became somewhat distracting before I had finished the meal. The spice came from the meat itself, with the taco al pastor even hotter than the beef cheek taco. I guess the meat is marinated in spices, or chiles are added during cooking, or both. With the base level of heat present, I couldn't stand to add more than a slight drizzle of salsa, offered in multiple versions, all of which also seemed very hot.
So my question is, is this typical? I'd like to hear some experienced taco hounds chime in with their opinions. Are authentic tacos usually spicy across the board? With the exception of fish tacos for example, would I be on a fool's quest to search for a milder version of an authentic taco? Is that a contradiction in terms?