If you're the type who always has a bottle of hot sauce at the ready or scan restaurant menus for the spiciest options, you're not alone. Spicy foods have become one of the hottest (literally) dining trends, with more of us than ever craving a kick. But what drives the burn in our favorite spicy dishes? What is the essential ingredient propels a food from flat to fiery? Here, we explore six famous foods from Buffalo wings to the ubiquitous Sriracha hot sauce to see how they get their heat.