Hot Ice refers to a chemistry demonstration involving a supersaturated solution of Sodium Acetate which, when disturbed, will appear to freeze into “ice” as the cold solution turns from a liquid into a solid in a matter of seconds. This process is exothermic and the resulting “ice” is warm to the touch, contrary to what one would expect of ordinary ice. The picture to the left depicts pillars of Sodium Acetate Trihydrate which were created using Hot Ice solution. Supersaturated solutions of Sodium Acetate are used in certain types of hand-warmers. When a metallic button is pressed inside a plastic pouch, the supersaturated solution begins to crystallize, in the process releasing heat. Sodium Acetate is one of the products of the reaction between baking soda (Sodium Bicarbonate, NaHCO3) and vinegar (Acetic acid, HC2H3O2