Book excerpt: Antifreeze proteins, also known as thermal hysteresis proteins, ice binding proteins and ice structuring proteins, prevent the growth of ice crystals in several cold blooded organisms. First discovered in fish, they have also been found in insects, plants, fungi and bacteria. Antifreeze proteins cause the non-colligative depression of the freezing point of water, a property which has been exploited in the practical applications of antifreeze proteins such as improving the texture of ice cream, and could be used to extend the crop growing season or allow fish to thrive in cold waters. This book provides clear information on what is known about antifreeze proteins today and how to study them.