You touch the four plates of plastic, aluminium, plexiglass and carpet with your palm.
All panels are exposed to the air and therefore have the same temperature. Nevertheless, the carpet seems to be warmer than the aluminium or plastic plate. Our perception of temperature deceives us.
Further informationson the exhibit "Temperature sensation"
The cause for the different temperature sensation is the different heat conductivity of the plate materials. The warm hand (approx. 36 degrees Celsius) gives off heat to the colder (approx. 20 degrees Celsius) plate surface. From there, the heat is conducted into the interior of the plate and withdraws this heat from the hand.
The greater the thermal conductivity of the plate material, the more heat is removed from the hand surface, which our sense of temperature misinterprets as a lower temperature.