What are some example organisms that have and use the thermoreceptor?

Thermoreceptors are free nerve endings tin the skin, liver, and skeletal muscles, and in the hypothalamus. They code absolute and relative changes in temperature. Every organism with a nervous system can detect changes in temperature. Example is the polar bear, which can function both in a zoo during summer heat and on an ice floe in frigid Arctic waters. Also the body temperature of poikilothermic animals, such as insects, snakes, and lizards, changes in direct relation to fluctuations in the temperature of the environment.