The goal of this study was to determine the effect of changes in core body temperature on the resting discharge rate and sensitivity of vestibular-nerve afferents. Extracellular recordings were made from vestibular-nerve afferents innervating the semicircular canals in anesthetized C57BL/6 mice maintained at a core body temperature of either 30-32 degrees C (T (31)) or 35-37 degrees C (T (36)). The resting rates of regular (CV* < 0.1) and irregular afferents (CV* > 0.1) were lower at T (31) than at T (36). Sensitivity and phase were compared for rotations ranging from 0.1 to 12 Hz by calculating coefficients of a transfer function, g . t(c)S . (t(z)S +1)/(t(c)S + 1), for each afferent. The sensitivity (g) increased with CV* and with higher core body temperature. The value of the coefficient representing the low-frequency dynamics (t (c)) varied inversely with CV* but did not change with core body temperature. The high-frequency dynamics represented by t (z) increased with CV* and decreased with higher core body temperature. These findings indicate that changes in temperature have effects on the static and dynamic properties of vestibular-nerve afferents.