A material temperature sensor comprising: an outer tube, and a sensor assembly within said tube including an elongated, magnetically susceptible temperature-sensing primary microwire having a re-magnetization response under the influence of an applied alternating magnetic field and operable to sense the temperature of said material over a selected temperature range, said primary microwire re-magnetization response being defined by at least one short, detectable pulse of magnetic field perturbation of defined duration and different above and below a primary microwire set point temperature, said primary microwire set point temperature being at or below the Curie temperature of the primary microwire, said tube being formed of a substance which does not appreciably magnetically bias said primary microwire, such that the presence of said tube does not significantly alter the re-magnetization responses of said primary microwire, said tube being substantially rigid and formed from a substance which resists changes in the shape of the tube, said substance selected from the group consisting of paramagnetic metals, metals having near-zero or zero magnetization, glasses, ceramics, and high-temperature synthetic resin polymers, said tube operable to substantially prevent forces exerted on the tube by the material of which the temperature is being sensed from distorting said sensor assembly within said tube, characterized in that said tube is close-ended, said sensor assembly further includes an elongated, magnetically susceptible temperature-sensing secondary microwire (18 or 20) having a re-magnetization response different than the re-magnetization response of said primary microwire under the influence of said applied alternating magnetic field, said secondary microwire re-magnetization response being defined by at least one short, detectable pulse of magnetic field perturbation of defined duration and different above and below a secondary microwire set point temperature, and said primary and secondary microwires (16, 18 or 20) are adhered together to form a microwire bundle, said bundle operable to maintain the relative positions of the primary and secondary microwires (16, 18 or 20) within said tube. an outer tube, and a sensor assembly within said tube including an elongated, magnetically susceptible temperature-sensing primary microwire having a re-magnetization response under the influence of an applied alternating magnetic field and operable to sense the temperature of said material over a selected temperature range, said primary microwire re-magnetization response being defined by at least one short, detectable pulse of magnetic field perturbation of defined duration and different above and below a primary microwire set point temperature, said primary microwire set point temperature being at or below the Curie temperature of the primary microwire, said tube being formed of a substance which does not appreciably magnetically bias said primary microwire, such that the presence of said tube does not significantly alter the re-magnetization responses of said primary microwire, said tube being substantially rigid and formed from a substance which resists changes in the shape of the tube, said substance selected from the group consisting of paramagnetic metals, metals having near-zero or zero magnetization, glasses, ceramics, and high-temperature synthetic resin polymers, said tube operable to substantially prevent forces exerted on the tube by the material of which the temperature is being sensed from distorting said sensor assembly within said tube, characterized in that said tube is close-ended, said sensor assembly further includes an elongated, magnetically susceptible temperature-sensing secondary microwire (18 or 20) having a re-magnetization response different than the re-magnetization response of said primary microwire under the influence of said applied alternating magnetic field, said secondary microwire re-magnetization response being defined by at least one short, detectable pulse of magnetic field perturbation of defined duration and different above and below a secondary microwire set point temperature, and said primary and secondary microwires (16, 18 or 20) are adhered together to form a microwire bundle, said bundle operable to maintain the relative positions of the primary and secondary microwires (16, 18 or 20) within said tube.