The non-stationary problem of thermoelasticity for rotating bodies has been solved through determining the optimal temperature and stress fields in the rolling mills of hot rolling systems, this determination being an issue of the day. The Eulerian approach was applied, it allowed us to reduce the number of independent variables and consider these fields as quasistatic ones. The heavy temperature gradients and stresses bound up with them, as well as the rotating nature of these fields are typical for the processes taking place in the roll core. To solve the problem of simulation of these processes, we proposed to use Fourier series, which allowed us to obtain a solution with a sufficient accuracy for the large number of terms of the series being considered. The peculiarity of the solution obtained is that the stress maximum locates at an insignificant depth beneath the roll surface.