A fog machine is a device, used primarily in theatrical environments, which converts a water-based fluid into a dense smoke.
This generated smoke is perfectly breathable, meaning that, in most cases, it is safe for individuals with breathing complications.
Fog machines are used many times to add erie effects to the stage in such plays like Dracula, A Christmas Carol, and Macbeth.
Such machines are frequently used in halloween displays such as haunted houses or forests. Because of recent (2003-2005) price
changes and avalability, fog machines can be seen on the doorsteps of everyday houses during the season of halloween.