Millimeter wave imaging devices are provided. A millimeter wave imaging device includes a housing and one or more heating elements inside the housing. The millimeter wave imaging device includes a flexible gasket on the housing. The millimeter wave imaging device includes a main lens attached to the housing by the flexible gasket. The millimeter wave imaging device includes a protective lens on an outer surface of the main lens. Moreover, the millimeter wave imaging device includes an Electromagnetic Impulse (EMI) filter attached to the housing and extending along an inner surface of the main lens. Methods of operating millimeter wave imaging devices are also provided.