Thermal shock
热冲击
Rapid, uneven temperature change that makes a pan or its coating crack or warp. Cast iron itself takes it better than enamel: bare iron warps, enamel chips.
In the kitchen
Pouring cold water into a hot pot to cool it is the classic way to crack enamel or bow a base. Every record on this bench cools pans on the hob instead.
Common misreading
Cast iron is not shockproof just because it is thick. A 250 °C skillet moved straight into cold water will usually survive, but it will rock on the counter for the rest of its life.