Exo Terra Thermostats should be set according to the needs of the animals. Thoroughly research the preferred optimum temperature (POTR) and humidity range for your specific reptile, so you can create the correct temperature gradients and humidity inside the terrarium to allow your reptiles to thermoregulate and maintain their moisture levels. With the Exo Terra Thermostats you can create a well-controlled 24-hour heating/humidifying system that allows you to maintain the required temperature and humidity conditions similar to those found in desert and tropical environments. The Thermostats will also help to prevent overheating and undercooling during hot summer days or cold winter nights.