A one-dimensional, high-latitude ionospheric model is constructed for solving the continuity, momentum, and energy equations numerically. With the assumption that field-aligned currents (FACs) be carried by thermal electrons in the polar ionosphere, the response of the ionospheric temperature to upward and downward FACs is studied. The results show that at altitudes higher than the F-region maximum, the electron temperature, Te, increases in upward FACs and decreases in downward FACs, consistent with what satellite observations indicate. These changes are caused by expansion/contraction effects due to drift of electrons along magnetic lines of force. It is also shown that Te increases in upward FACs more efficiently than it decreases in downward FACs. In downward FACs the ion temperature, Ti, increases, although the response is not as sensitive as that of electrons. For downward FAC cases, Te is also found to increase for a larger magnitude of FACs. In the present calculations, Te decreases only in the magnitude range between 0 and 130 ¿Am-2 for downward FACs. The temperature increase in upward FAC regions with respect to the background temperature without FACs is not simply linearly related with the intensity of FACs.