In addition to shooting electricity from their fingers, wizards also seem to have a knack for generating walls of fire or flaming missiles from seemingly out of the blue. This magical ability may be a controlled form of the debatable phenomenon known as spontaneous combustion. Many scientists contend that it’s impossible for the human body to combust without an exterior heat source. However, there’s been concrete documentation of decayed plant matter bursting into flame due to bacteria generating an intense heat during decomposition. Therefore, do wizards have sway over their own bodies’ incendiary bacterial output? Perhaps, but it doesn’t explain why their skin isn’t burning to a crisp.