It’s a law of nature that hot air rises, which is why low-hanging fog can be such a difficult effect to pull off during theatrical productions. Still, certain shows call for a dreamy, fantastical atmosphere that is best portrayed with the presence of fog. There’s nothing worse than all-encompassing fog that obscures the performers’ faces, however. It becomes necessary to strike the perfect balance.
At first, many directors and stage hands turned to dry ice “pea souper” machines, which disperse ground-hugging carbon dioxide gas. Although suitable for creating the desired effect, these machines are exceedingly difficult to use and maintain. Fog machines with built-in coolers are specially equipped to create low lying fog. These machines run on fog juice rather than dry ice, and they are many times easier to handle.