A fluid control device includes a housing and a fluid temperature control assembly. The housing includes a first inlet, a second inlet for receiving a fluid, and a first outlet through which a fluid of a third temperature flows. The fluid temperature control assembly is in the housing, with apertures for regulating fluid communication between a mixing cavity and the first inlet of the housing, apertures communicating with the first outlet. The fluid temperature control assembly modifies properties of the apertures for regulating the amount of fluid having a first temperature relative to the amount of fluid having a second temperature with the mixing cavity, thereby maintaining the fluid discharged from the first outlet at a predetermined temperature.