Dry ice, or solid carbon dioxide, is the solid state of CO gas below -109.3 °F (-78.5°C). Dry ice does not occur naturally on earth but is man made. It is colorless. People use dry ice to make things cold, and to make drinks fizzy, kill gophers, and freeze warts. The vapor of dry ice causes suffocation and eventually, death. Caution and professional assistance is recommended whenever dry ice is in use.