You may have noticed that a bicycle pump becomes warm when you fill a bicycle tire with air. This happens because the rapid compression of air adds heat (thermal energy) to the air. The moving piston of the pump increases the speed of the air molecules bouncing from it, thus increasing the air temperature inside the pump.
The temperature change may be quite large, enough to exceed the autoignition point of any materials inside the pump. If so, they burst into flames or smolder upon compression. The diesel engine has no spark plugs but produces autoignition by the same compression or adiabatic heating principle.
Compressing the Fire Syringe can produce a momentary flame from autoignition of the cotton inside. If the cotton is “oily” the autoignition temperature is cut in half to approximately 120 degrees C. Indeed 3-in-1 Oil dampened and dried cotton or paper ignites more easily than dry cotton or paper. Tinged paper from one compression is shown to the right