Hot sauce has long been the domain of the South. Heat begets heat, as it were. But the warmer side of the Mason-Dixon is not the only place good hot sauce can be found. Out to prove Yanks can handle their spice are the nearly 40 participants from around the country in the first annual New York City Hot Sauce Expo, to be held April 20 and 21 at Brooklyn’s East River State Park. Read on.