Abstract: A flow resistor having a flow conduit with an inlet opening and an outlet opening, and a membrane forming a wall of the flow conduit, and a cross section of the flow of the flow conduit can be varied by exerting pressure on the membrane. The flow resistor has a cavity containing a medium with a positive temperature coefficient and a flow chamber; the membrane separates the cavity from the flow chamber and is both the wall of the cavity as well as the wall of the flow conduit, wherein the flow conduit is constructed as a helical recess, open to the membrane, in a surface of a lower cover that closes the flow chamber, wherein an inflow opening is arranged in the center of an area fixed by the flow conduit and wherein an outflow opening is arranged on the edge side.