Abstract: In a sprinkler system for warehouse freezers or other cold environments, a sprinkler system piping connected to a water supply through a check valve and extends through a freezing cold environment to sprinkler heads positioned to discharge extinguishant. The sprinkler system piping within the cold environment is filled with a solution of potassium lactate. When a fire occurs causing one or more of the sprinkler heads to be activated, the sprinkler heads will discharge the potassium lactate onto the fire. This action will reduce the pressure in the sprinkler system piping bellow that of the water supply so that water flows from the water supply through the sprinkler system piping through the activated sprinkler heads to be discharged upon the fire.