Since pressurisation forces are to be resisted by flight deck windows as well as the cabin structure, the windows need to be very strong. To achieve this, flight deck windows are constructed from several layers. Heating elements are added to the tough outer glass. There are two main benefits of heating:

• The first is icing resistance due to the increased temperature of the surface. Windshield heat controllers are generally capable of handling two primary functions: de-fog and de-ice. Cockpit side windows often do not feature window heating but are only equipped with defogging devices.

• The second is that the heated glass stays in a temperature range where it is less rigid. The heating elements usually heat the windows into this temperature range, switch off so they do not overheat, then switch back on again if the window is going to cool down too much, cycling like this throughout every flight. Window heating ensures the screen vinyl layer is kept elastic and resilient and better to absorb damage in case of a bird strike/hail. For this reason most, if not all, commercial aircraft with heated windshields will have a speed restriction below 10 000 ft if the windshield heat is inoperative, commonly that restriction is to be not above 250 KIAS below 10 000 ft.