Thermal fogging machines are used to create fog with ultrafine particles that mimic smoke and can penetrate deeply into cracks and crevices. Used most often for deodorizing large spaces, these foggers are used in massive remediation or restoration projects and can be used with a variety of water-based chemicals. These types of foggers are the preferred type for outdoor fogging projects, and the smoke created is usually white, easy to see, and ensures that fog reaches all intended spaces.