Unless you are flying an aircraft that has a certified ice protection system (IPS), the decision to fly into the clouds when the static air temperature is at or below 0 degrees Celsius often means some risk of structural icing. Whether or not structural icing is possible is completely dependent on the liquid water content (LWC) in the cloud, cloud drop size and the total temperature, also known as the skin temperature of the aircraft. Of course, not all clouds are the same. Some clouds are not an icing hazard and contain very small drops that tend not to penetrate the boundary layer of the airframe. Other clouds contain little or no supercooled liquid water content and are mostly composed of ice crystals. The latter is usually a function of temperature. In this workshop we will examine the conditions that are just too cold to support supercooled liquid water.