At work impact of temperature of polymeric melts on the sizes and intensity of the vortex area arising in case of a flow on an entrance to the slot channel is considered. For mathematical description of a three dimensional flow of melts in the converging channel the modified Vinogradov and Pokrovskii rheological model is used. The model is generalized for accounting of non-monotonic behavior of gradient dependence of elongation viscosity. Also Newtonian law for residual viscosity is used. Temperature dependence of initial shear viscosity of polymeric melts has the Arrenius appearance. Initial relaxation time was estimated as by comparison with experimental data for gradient dependence of stationary viscosity in case of uniaxial elongation, and on the basis of molecular and kinetic approach. Sticking conditions for velocity on a wall have been used. Discrete analogs of system of the equations of dynamics of polymeric fluid were by method of control volume with separation on physical processes. In case of implementation of numerical algorithm the possibility of application of parallel calculations technology based on graphical processors was considered. In numerical experiments returnable courses of polymeric melts before an entrance to narrow part of the canal are found and it is shown that dependence of the vortex sizes and intensity on temperature of melt has non-monotonic character and passes through a maximum. It is also shown that polymeric flow before an entrance to the slot-hole channel has significantly three-dimensional character, the sizes of the vortex area calculated in the sections which are carried out at various distances from an axis of the channel in the beginning increase in case of approach to a firm wall, and then decrease. All features noted in calculations are observed also in real experiments on branched polyethylene of low density melts.