In this paper, a nonlinear electrical model is derived and is used to calculate the electric field and the current density. To corroborate our electrical model, it was compared to TCAD simulator. It was shown that the proposed model captures the current density with a good degree of agreement with TCAD simulator. The electrical model is given by the modified Drift-Diffusion (D-D) model coupled with the Ballistic-Diffusive Equation (BDE) which is able to predict the heat transfer phenomenon in the nanoscale regime. The thermal device performance is then investigated by varying device parameters including gate and drain biases with implementation of different gate dielectric to explore its response on thermal characteristics. It was further shown that the proposed electro-thermal model is able to predict the nano heat conduction in (DG) nanostructure devices. In addition, it is shown that the heat flux process could be controlled by adjusting the drain and gate voltages.