An apparatus comprising: a heating device (60, H1, H2) comprising a controllably heatable thermally conductive heating element (H1, H2); a nozzle for injecting fluid material from an injection molding machine through a flow channel in a heated manifold, comprising a tube of thermally conductive material having an outer surface and an inner surface defining a central flow bore having an axis extending from an upstream end to a downstream end of the central flow bore, the central flow bore being couplable to the flow channel of the manifold and a cavity of a mold; the heating element (H1,H2) of the heating device being mounted on or around the outer surface of the thermally conductive tube of the nozzle such that heat is transferable between the heating element and the outer surface of the thermally conductive tube of the nozzle, the heating element extending along the axis of the central flow bore of the thermally conductive tube of the nozzle to an end point of the heating element; a temperature monitor (S1, S2) for measuring the temperature of the nozzle, comprising a temperature sensor mounted on or around the thermally conductive tube of the nozzle at a selected position along the axis of the central flow bore of the thermally conductive tube of the nozzle, the temperature monitor comprising a thermocouple comprised of elongate wires (S1,S2); an elongated tube comprising a thin-walled sheath comprised of a thermally conductive material, an interior bore and having a length, the elongated tube wound around the thermally conductive tube of the nozzle extending along the axis of the central flow bore of the thermally conductive tube of the nozzle, with the heating element (H1,H2) and wires (S1,S2) connected to the temperature sensor extending through the interior bore of the elongated tube, the elongated tube being mounted in thermally conductive contact (20, 40) with the thermally conductive tube of the nozzle on or around the thermally conductive tube of the nozzle, characterised by a thermal insulator disposed along the axis of the central flow bore of the thermally conductive tube of the nozzle separating the end point of the heating element and the temperature sensor; and in that the heating element and the wires (S1,S2) separately terminate at first and second distal positions (HEP, T) along the length of the elongated tube such that the end point of the heating element and the temperature sensor are separated axially along the axis of the central flow bore of the thermally conductive tube of the nozzle by a distance of at least about 3.18 mm (about 0.125 inches). a heating device (60, H1, H2) comprising a controllably heatable thermally conductive heating element (H1, H2); a nozzle for injecting fluid material from an injection molding machine through a flow channel in a heated manifold, comprising a tube of thermally conductive material having an outer surface and an inner surface defining a central flow bore having an axis extending from an upstream end to a downstream end of the central flow bore, the central flow bore being couplable to the flow channel of the manifold and a cavity of a mold; the heating element (H1,H2) of the heating device being mounted on or around the outer surface of the thermally conductive tube of the nozzle such that heat is transferable between the heating element and the outer surface of the thermally conductive tube of the nozzle, the heating element extending along the axis of the central flow bore of the thermally conductive tube of the nozzle to an end point of the heating element; a temperature monitor (S1, S2) for measuring the temperature of the nozzle, comprising a temperature sensor mounted on or around the thermally conductive tube of the nozzle at a selected position along the axis of the central flow bore of the thermally conductive tube of the nozzle, the temperature monitor comprising a thermocouple comprised of elongate wires (S1,S2); an elongated tube comprising a thin-walled sheath comprised of a thermally conductive material, an interior bore and having a length, the elongated tube wound around the thermally conductive tube of the nozzle extending along the axis of the central flow bore of the thermally conductive tube of the nozzle, with the heating element (H1,H2) and wires (S1,S2) connected to the temperature sensor extending through the interior bore of the elongated tube, the elongated tube being mounted in thermally conductive contact (20, 40) with the thermally conductive tube of the nozzle on or around the thermally conductive tube of the nozzle, characterised by a thermal insulator disposed along the axis of the central flow bore of the thermally conductive tube of the nozzle separating the end point of the heating element and the temperature sensor; and in that the heating element and the wires (S1,S2) separately terminate at first and second distal positions (HEP, T) along the length of the elongated tube such that the end point of the heating element and the temperature sensor are separated axially along the axis of the central flow bore of the thermally conductive tube of the nozzle by a distance of at least about 3.18 mm (about 0.125 inches).