Abstract: A heater cable, which may particularly be a self-regulating heater cable, has a heating element including two bus wires spaced a distance apart by a positive temperature coefficient (PTC) material, giving the heating element a major axis and a minor axis. Bending the heater cable transverse to the major axis gives a tighter bend radius than bending the heater cable transverse to the minor axis. To facilitate bending in multiple directions, the heating element is twisted around the longitudinal axis of the heater cable. The twisting may be done uniformly to give the bus wires a helical configuration, which reduces electromagnetic interference and facilitates heater cable diameters as small as 0.25 inches. Additional layers, such as polymer jackets and a braided metal ground plane layer, may be added over the heating element. Each of these layers may be twisted or untwisted in various implementations.