In sub-isothermal glaciers heat conduction plays the main role in the formation of the temperature field, and the contribution of advection is relatively small. The dependence of the strain-rate on the temperature is simplified by a linear approximation. If the whole range of the temperature change in a glacier does not exceed ≈ 3 deg, with the power rheological law the quasi-steady temperature distribution is described by a simple analytical dependence. In the upper part of the ice, the temperature varies with depth almost linearly; the deflection from the linear distribution is essentially in the lower part.