A method of reducing thermal stresses of a semiconductor component in a frequency converter, an arrangement in a frequency converter, and a frequency converter, wherein the semiconductor component is attached to a cooling element for cooling the semiconductor component and one or more resistive elements are attached to the cooling element. In the method, the cooling element is heated by the one or more resistive elements attached thereto by supplying current from the frequency converter through the one or more resistive elements for obtaining an elevated lowest temperature for the semiconductor component and thereby reducing the amount of temperature change between the highest and the lowest temperatures in the semiconductor component during use of the frequency converter.