A fog-generating system (1) is described, comprising: a tank (5) containing fog-generating fluid; a pump (3) connected to the tank (5) to withdraw the fog-generating fluid therefrom; a serpentine (2) connected to the pump (3) to receive the fog-generating fluid pumped by the pump (3), the serpentine (2) being divided into a first section (A) connected to the pump (3) and a second section (B) connected to the first section (A) and designed to emit dry fog (7) as output; a battery (6) connected to the serpentine (2) to pass electric current inside the serpentine (2) and to supply the pump (3); a differential amplifier (11) connected to the second section (B); and a threshold comparator (13) which, upon exceeding a certain voltage, a stop index of the serpentine (2) in the second section (B), breaks the supply to the pump (3).