How could Dracula prowl the stage without blankets of fog rolling in from the wings? While fog itself is simple chilled water vapor, producing it onstage is tricky. Special machines create the fog which is then super-cooled. Sometimes ice or dry ice is used, but this year we’re using a recyclable cooling substance, super cooled isopropyl alcohol. Since its freezing point is -117 degree Fahrenheit, the fog can be really cold, so cold that it (mostly) stays creepily low to the ground. We do our best to steer the fog in the right direction but, don’t worry if a little spills into the audience, it will not make you cough.