I ate in a local Chinese restaurant last night. I ordered a Sichuan dish and ask that it be prepared "extremely hot". It came out as medium. Perhaps "extremely" didn't translate well making it my error. That's not my point.
I like spicy food. If a given take out dish isn't hot enough, I'd like to be able to have a few condiments on hand to raise the heat. Adding tabasco to a Thai dish doesn't seem right. What are the other common ingredients in a given cuisine that make dishes hotter?
From my handy Sichuan cookbook, I know that chili oil and Sichuan chili powder are common condiments that bring the heat.
What about other cultures?