The main function of the mid layer is to insulate and warm. At the same time, it
also transports moisture. The thickness of the garments in layer 2 varies depending on the temperature and weather. It is by putting on and taking off this layer that the body temperature is best regulated. A good middle layer could be, for example, a thicker wool sweater or a fleece. Which garment to choose depends on your activity level. For pulse-raising activities, a fleece with good breathability is ideal.