A heat gun is a device used to emit a stream of hot air, usually at temperatures between 100 °C and 550 °C (200-1000 °F), with some hotter models running around 760 °C (1400 °F), which can be held by hand. Heat guns usually have the form of an elongated body pointing at what is to be heated, with a handle fixed to it at right angles and a trigger, in the same general layout as a handgun, hence the name.
A heat gun comprises a source of heat, usually an electrically heated element, but sometimes a gas flame; a mechanism to move the hot air such as an electric fan, unless gas pressure is sufficient; a nozzle to direct the air, which may be a simple tube pointing in one direction, or specially shaped for purposes such as concentrating the heat on a small area or thawing a pipe but not the wall behind; a housing to contain the components and keep the operator safe; a mechanism to switch it on and off such as a trigger; a handle; and a built-in or external stand if the gun is to be used hands-free. Although not called such, a hair dryer is a form of low-temperature heat gun. Gas-powered soldering irons sometimes have interchangeable hot air blower tips to produce a very narrow stream of hot air suitable for working with surface-mount devices and shrinking heat shrink tubing.
Heat guns are used in physics, materials science, chemistry, engineering, and other laboratory and workshop settings. Different types of heat gun operating at different temperatures and with different airflow can be used to strip paint, shrink heat shrink tubing, shrink film, and shrink wrap packaging, dry out damp wood, bend and weld plastic, soften adhesives, and thaw frozen pipes. Heat guns, often called hot air guns or hot air stations for this application, are used in electronics to desolder and rework surface-mounted circuit board components. Heat guns are also used for functional testing of overheat protection devices, in order to safely simulate an overheat condition.