Pb0.97 La0.02 (Zr0.65 Sn0.22 Ti0.13) O3 ceramic was confirmed to be in an antiferroelectric (AFE) phase at T<170 °C by macroscopic and microscopic studies. The electric-field-induced ferroelectric (FE) state was found to exhibit a much longer lifetime than the reasonable laboratory measuring time scale at T<60 °C, which has led to the frequent misinterpretation of this material system as FE. The dc bias dependence of the dielectric and pyroelectric properties was studied as a function of temperature. The poled sample exhibited a low dissipation factor (tan δ∼0.03), a large transient pyroelectric coefficient of the order of 10-3 - 10-2 Cm-2 K-1, and excellent dc tunability at the FE-to-AFE transition temperature (39 °CkVmm). The possible application of this material to uncooled tunable pyroelectric thermal sensing is also discussed.