Of cold and warm materials
When we touch different materials, we can feel different temperatures, even if these materials have the same temperature on the surface.
Wood or leather, for example, are “warm” materials. We feel a comfortable temperature when we touch it with our finger or hand. This is not the case with stainless steel or aluminum, we feel a certain cold here. Even though a thermometer would measure the same temperature on the materials. How does this contradiction come about?
This is a delusion of our perception that can be easily explained: It’s about the different thermal conductivity of the respective material. Our hand gives off heat when it is touched or touched. This emitted heat is absorbed and conducted differently into the interior of the object. Times more when we feel cold (because heat is drawn away from us); sometimes less when we feel warmth (because our hand hardly gives off any heat due to the low thermal conductivity).
This principle is used in house construction for thermal insulation by using the low or poor thermal conductivity of wood or foam to insulate the inside of the house from the cold outside air.
When cooking, on the other hand, the thermal conductivity of metal is used to warm up the pot or pan quickly.