Oh Fell. It Seems To Have Triggered...
Body & Soul0 min ago
No best answer has yet been selected by thrappy. Once a best answer has been selected, it will be shown here.
For more on marking an answer as the "Best Answer", please visit our FAQ.The most common type you see on films etc is made from 'Dry Ice' which is frozen carbon dioxide, when you drop it int boiling water it produces the fog efect you'r after.
You can hire dry ice machines from theatrical hire shops.
I have seen it done on a small scale using a flask of dry ice poured into a bowl and adding hot water but both dry ice and boiling water are obviusly dangerous and must be handled with extreme care! (dry ice can stick to your skin and givre you a frost burn)