Dry Ice

[trailhound]

The Halloween business is what prompted my question about putting dry ice in water. I was helping with such an activity at a historical site, and was carrying a bucket that was supposed to produce said fog from dry ice in water. Instead, the water around the ice kept freezing, and no fog came out.

I have never tried to make fog but I recall instructions that say to use hot water. That way, fog is made before the water freezes.