Most species operate at a preferred optimum temperature zone ([[Preferred optimum temperature zone|POTZ]]). Studies of free-ranging iguanas show that body temperatures are maintained between 35°C and 37.8°C during daytime and between 24°C and 27°C during sleep. | Most species operate at a preferred optimum temperature zone ([[Preferred optimum temperature zone|POTZ]]). Studies of free-ranging iguanas show that body temperatures are maintained between 35°C and 37.8°C during daytime and between 24°C and 27°C during sleep. |