The paper presents the results of researches of temperature variations during flat peripheral grinding. It is shown that the temperature variations of the workpiece can reach 25...30% of the average values, which can lead to some thermal defects. A nonlinear two-dimensional thermophysical grinding model is suggested. It takes into account local changes in the cutting conditions: the fluctuation of the cut layer and the cutting force, the thermal impact of the cutting grains, and the presence of surface cavities in the intermittent wheel. For the numerical solution of the problem, the method of finite differences is adapted. Researches of the method stability and convergence are made, taking into account the specific nature of the problem. A high accuracy of the approximation of the boundary conditions and the nonlinear heat equation is provided. An experimental verification of the proposed thermophysical model was carried out with the use of installation for simultaneous measurement of the grinding force and temperature. It is shown that the discrepancy between the theoretical and experimental values of the grinding temperature does not exceed 5%. The proposed thermophysical model makes it possible to predict with high accuracy the temperature variations during grinding by the wheel periphery.