The application of patterned electrically conductive (EC) coatings in infrared systems is discussed. The design approach, calculated and experimental performance for two different components are described. One component is a 9.5" diameter window of clear ZnS with an EC grid coating to provide deicing/defogging capabilities for a shipboard FLIR System. The heating uniformity and optical performance of the window were evaluated. The second patterned EC coating is an electromagnetic interference (EMI) shield on a window of ZnSe with a thin ZnS outer layer for improved mechanical properties with little loss of optical properties. The optical and shielding performance of this coated window for an aircraft thermal IR imaging system is reported.