As the name shows, a Thermal fogger uses heat to vaporize a fogging liquid. In most cases, this liquid is an insecticide or pesticide. It sprays the liquid out of the nozzle of the fogger in the form of a mist or a fog. Thermal foggers have a storage tank that can hold upto 10 L of liquid. This container, which holds insecticide or other fogging liquids, is located on the bottom of most foggers.