A device for the thermal fogging of a liquid, includes a unit for producing a stream of pressurized hot gas an ejection pipe; a first source of liquid; and a first circuit for injecting a measured flow of liquid into the ejection pipe (5) from the first source of liquid. In addition, the device includes a sensor for detecting a total or partial interruption of the measured flow of liquid injected into the ejection pipe from the first source of liquid; a second source of liquid; and a second circuit for injecting an emergency flow of liquid into the ejection pipe from the second source of liquid when the sensor detects a total or partial interruption of the measured flow of liquid injected into the ejection pipe from the first source of liquid.