One time I went to an Indian restaurant with my boss (from south India) and a Mexican coworker. I ordered my food mild, my boss ordered his medium, and the Mexican guy ordered his hot. My boss tried to warn him but he insisted that he could handle spicy food.

The food came out, the Mexican guy had no problem eating his, and he started gloating. Then my boss told him that he was actually eating my boss's medium food. After they switched plates, the Mexican guy turned red, started sweating, and had to ask my boss to switch back.

(My boss had no problem eating the hot food; he just preferred the taste of medium.)