Experiments were performed on convection in a two-layer, stably stratified pool, in the SIMECO experimental facility: a semicircular slice vessel, with internal heat generation in one or both layers. The objective was to study lite effect of stratification on the heat transfer to the boundaries of the pool. Effects of miscibility or immiscibility of the layers and the density difference between the layers were investigated. The stratification with miscible fluids was established using salt water and pure water and that for immiscible fluids was established using pure water and paraffin oil. The concentration of salt in lite upper layer was measured using a conductivity probe. The results show that the presence of an interface significantly changes the heat flux distribution along the downward/sideward (semicircular) boundary, decreasing the ratio of up/down heat fluxes by a factor of 4. The mixing of the interface, when both the layers are internally heated, is complete only when Ri less than or equal to 5. The miring times for the two layers, when only the lower layer is internally heated are correlated by a simple relation between the fluid parameters and the heat input.