Mufflers deal with temperatures that range between 300 and 500 degrees Fahrenheit. Due to the intensity of heat produced by an engine's emission system, most exhaust systems are built to handle an excess of 1,200 degrees.
Although some of the heat in the exhaust system may disperse before leaving the tail pipe, a muffler can still be extremely hot. If the heat on an exhaust system exceeds its average temperature, then there may be an issue with the engine's emission system. The emission system should be quickly troubleshooted and repaired before continuing to use the vehicle, as the high temperatures can cause its catalytic converter to fail.