Heat receptors - but how do they work?

Our skin does feel temperature, but how does that work?

When you touch a hot stove, you can feel that right away. We want to find out what happens in our body when you do that.

Our skin is a specialized sensory organ with different receptors that are also called "feelers". These receptors are responsible to perceive feelings and transport them towards the brain. In the brain, the information is interpreted. Receptors are highly specialized. They can perceive pressure, pain, warmth or cold. There is an exceptional large amount of receptors in your finger-tips, some of them are touch receptors, and others heat receptors. These receptors react once the temperature around them changes. Just like in our example with the stove. Once the temperature difference is too high, the heat receptors (ruffini-receptors) send a signal to the brain. Inside the brain, the origin of the feeling is located. Your body then realizes that it should put the hand away from the hot stove as fast as possible. However, the heat receptors do not perceive the actual temperature, but the difference in temperature between the object and your own body temperature.

Image: thermoreceptors of our skin

The perception of low temperatures happens similarly: When you touch a cube of ice or snow for some time, the cold receptors (krause-receptors) realize that your skin cools down. This is a protection mechanism to prevent undercooling. Of course, not only your hands can feel heat or cold. This shows that the thermo receptors are located in the skin all over your body. They are located more or less deep under the surface of the skin. There are more cold receptors than heat receptors. In total there are between 10 and 20 million tiny thermo receptors in your body. But what can we say about objects that we touch?