The thermal shock resistance of ceramics is generally evaluated by the water-quench test, in which it is important and necessary to understand the heat-transmission behaviour. A novel and simple method for measuring the transitional changes of temperatures in ceramics has been proposed. Changes in temperature at two different positions in zirconia ceramics were measured to estimate the temperature distribution. From the analytical results, it was clear that the heat-transmission behaviour changed with the quenching temperature or water temperature. The Biot number also changed remarkably with time or with the surface temperature in this experiment. These results are useful in practice for examining the cooling conditions in the thermal shock test.