In one example embodiment, a valve can include a piston configured to open the valve when a first force is greater than a second force, a biasing member that pushes against the piston and exerts a substantial portion of the first force against the piston, and a material that exerts a substantial portion of the second force against the piston, wherein the material changes from a solid to a liquid at an approximate, predetermined temperature, the change of the material from solid to liquid decreases the second force and allows the piston to move and open the valve.