According to one embodiment of the invention, a system for regulating a temperature of a fluid through a conduit comprises a conduit, a moveable obstruction, an actuator, and a pressure generator. The conduit has an inlet, an outlet, and an opening between the inlet and the outlet. The inlet is operable to receive fluid into the conduit and the outlet is operable to dispense of fluid out of the conduit. The moveable obstruction is operable to at least partially cover the opening and thereby resist flow of fluid through the opening. The actuator has a chamber with a heat sensitive substance. The heat sensitive substance is operable to change a characteristic upon receipt of thermal energy from fluid traveling through the conduit. The actuator is additionally operable to move the obstruction upon the change in characteristic of the heat sensitive substance. The pressure generator is operable to apply pressure to the chamber to change a property of the heat sensitive substance. The change in property of the heat sensitive substance changes the movement of the obstruction by the actuator.