When a liquid, such as the water of Lake Servières, turns solid, it releases a large amount of heat called latent heat. It spreads through the water and keeps the lake from freezing all at once, protecting its fauna and flora. This phenomenon also allows the lake's waters to stay between 32° F and 39.1° F (0 and 3.98° C) for several months while the atmospheric temperature may drop to -50° F or -68° F (-10 or -20° C).