Pyroelectrics convert changes in temperature to electricity, which is of significant interest for sensing and energy harvesting applications. Applied voltages are usually required to generate pyroelectricity in antiferroelectrics due to the instability of the polar phase. By sandwiching 8 - 6 nm thick antiferroelectric ZrO_2-based films in between electrodes with different work functions, pyroelectricity was stabilized without an applied voltage. Simple voltage pulses were used to turn the pyroelectric effect off and on by setting ZrO₂ into a nonvolatile nonpolar and polar state, respectively. The result is a passive sensor capable of active on/off switching.