Abstract: A pesticide fogger suitable for use with internal combustion engines has a heat exchanger built into the exhaust. A pesticide line is run along the exhaust, its entry port is at the hottest point of the exhaust, suitably about 3 inches from the inlet end of the exhaust. The line is wound in counter current flow in six coils around the exhaust between the muffler and the entry port. An outer sleeve surrounds heat exchanger, exhaust and entry port to form a sealed chamber. The discharge pipe apertures in the muffler are at least 3/16 inch in diameter. The device is conveniently an exhaust component for attachment to an internal combustion engine, and is suitable for lawn mowers. A hand operated accordion primer pump built into the pesticide container conveniently provides initial positive pressure.