<P> In mammals, temperature receptors innervate various tissues including the skin (as cutaneous receptors), cornea and urinary bladder . Neurons from the pre-optic and hypothalamic regions of the brain that respond to small changes in temperature have also been described, providing information on core temperature . The hypothalamus is involved in thermoregulation, the thermoreceptors allowing feed - forward responses to a predicted change in core body temperature in response to changing environmental conditions . </P> <P> Thermoreceptors have been classically described as having' free' non-specialized endings; the mechanism of activation in response to temperature changes is not completely understood . </P> <P> Cold - sensitive thermoreceptors give rise to the sensations of cooling, cold and freshness . In the cornea cold receptors are thought to respond with an increase in firing rate to cooling produced by evaporation of lacrimal fluid' tears' and thereby to elicit a blink reflex . </P> <P> Warm and cold receptors play a part in sensing innocuous environmental temperature . Temperatures likely to damage an organism are sensed by sub-categories of nociceptors that may respond to noxious cold, noxious heat or more than one noxious stimulus modality (i.e., they are polymodal). The nerve endings of sensory neurons that respond preferentially to cooling are found in moderate density in the skin but also occur in relatively high spatial density in the cornea, tongue, bladder, and facial skin . The speculation is that lingual cold receptors deliver information that modulates the sense of taste; i.e. some foods taste good when cold, while others do not . </P>

Where are hot and cold receptors located in the body