Thermoreceptors

Thermoreceptors are sensory neurons that are activated by changes in temperature. They reside in the skin, liver, skeletal muscles, and in the hypothalamus. Some of them are activated by heat and others activated by cold, the latter being 3.5 times more common than the former.

Cold thermoreceptors normally activate when the tissue temperature falls below 25 °C celsius , while warm thermoreceptors are most active when the temperature rises above 45. Their activation triggers an action potential that transforms temperature changes into electrical information.