A detailed analysis of the region of multiple steady states in nonisothermal-nonadiabatic systems is performed. It is shown that in a certain region of Damköhler numbers five steady states are possible. These steady states are referred to as the kinetic, diffusion and intermediate regimes. Numerical procedures for calculation of regions of multiplicity are described. Numerical analysis of the problem indicates that with higher value of the cooling parameter β multiplicity is suppressed. For higher values of the Peclet number multiple steady states disappear. The analysis has shown that in nonadiabatic systems Frank-Kameneckij approximation of the temperature dependence of the reaction rate must be used with some care.