‘A two alarm fire is a fire that is too much for one firehouse’s resources to handle. When multiple agencies or groups are called in, the alarm count increases. Two firehouses are called in, vs. three, four or five.
Hence, 2,3, or 4 alarm chili from less to more heat in the spices. The bigger or more difficult the fire, the more alarms.The more, burn in the mouth, the more alarms.