If you have ever been a passenger on a motorcycle, you were probably warned by the driver to keep your leg away from the exhaust pipe so you wouldn't get burnt. An exhaust pipe can actually get red hot, especially on a hot day.
The Exhaust System
Vehicles with internal combustion engines, including cars, trucks and motorcycles, use an exhaust system to remove the heat and fumes produced by the engine. The exhaust pipe is usually made of steel but can be stainless or aluminised steel tubing.
The temperature of an exhaust pipe during operation of the vehicle depends on the type of metal, the distance from the engine, the temperature of the ambient air and the length of operation. Metal begins to glow faintly at 482 degrees Celsius (482C). A tailpipe that's visibly red in the sunlight is about 704C (704C). That's hot enough to roast hot dogs and marshmallows without a campfire.
To avoid burns from motorcycle exhaust pipes, the National Institute of Health recommends passengers wear long trousers, and owners install a heat shield around the exhaust pipe to reduce the surface temperature.