A sprinkler head for use in a structure for the delivery of a liquid includes a housing, a sleeve, a cap, a spray assembly, a return spring and an SMA spring. The sleeve includes a first portion which is positioned in the housing. The cap is threadedly assembled with the housing. The spray assembly is assembled to a second portion of the sleeve. The return spring is positioned between the cap and the first portion. The SMA spring is positioned between the cap and the spray assembly. The sleeve is movable relative to the housing in order to open a liquid flow path due to activation of the SMA spring resulting from an elevated temperature.