Generally, the best way to escape from icing conditions is to make a 180-degree turn, since this tactic will put the aircraft back into an area where the pilot knows there is no icing. The next best alternative is to climb. Unless there is a temperature inversion, the air at higher altitudes will be colder and moisture will exist in the form of ice crystals that will not stick to the airframe. Icing layers are generally not more than 3000 feet thick, except in the case of towering cumulous clouds. Descending to warmer air is also a possibility, but pilots should remember that there will be no guarantee of escaping from the icing conditions. Once the descent has been made, additional accumulations of ice will probably prohibit climbing again.