Abstract: A fire extinguishing apparatus (1) comprising a container (2) for heated water. An outlet (10) for heated water is provided in a manifold (11) which defines an insulating leg for cooler water. A valve (15) is operated to release heated water through the outlet to a discharge head (35). A heating element having an unheated portion (16) in the insulating leg, a high output heating portion (17) and a low output heating portion (18) extends into the container to maintain the heated water at a desired temperature. A pipe (25) extends from an open inlet at a level L in the container to the manifold (11). On operation, a valve (27) on the pipe (25) is opened to release steam from the head space in the container to the discharge head (35). The heated water head (35) breaks up the heated water mass into a micromist of finely dispersed water droplets which forms a highly efficient and safe extinguishant.