In addition to their use in Mexican food, chiles are also used extensively in other cultures’ cuisines such as Thai, Hunan, Szechuan, East Indian and African.  Most hot food originates in countries with hot climates (we always say that we need the hot foods in our colder climates to stay warm, from the inside out!).  One of the likely reasons for this is that spice was probably used to mask spoiled food when refrigeration wasn’t yet available.  Another reason is that eating hot food creates perspiration, which creates an “air-conditioning” system when air evaporates the moisture on skin and garments.