When metallic nanostructures are illuminated under resonance condition, part of the intercepted light is dissipated through nonradiative damping, resulting in a dramatic rise in temperature in the nanometer-scale vicinity of the particle surface. This nanoscale heat has been of great interest for applications in biomedicine and solar energy. We investigate the generation of heat in gold nanostructures at a constant metal volume and different morphologies under excited surface plasmonic resonance conditions using the finite-difference time-domain method and solving the thermal equation as well. Heat power as a measure of thermal efficiency has been obtained for different morphologies. Two kinds of structures including colloidal-like nanoparticles and lithographic planar nanostructures are discussed. It has been observed that as the surface-to-volume ratio in the structure increases, the heat power also increases along with a redshift, and the maximum increase is obtained for the porous structure. The amount of light transmission through porous nanostructure has also been investigated, compared with the nonporous structure, and it has been observed that they present better optical transmission. And therefore, they would have more desirable performance in multilayered structures. Moreover, the influence of surrounding medium on thermal and transmission characteristics of the nanostructures has been studied. Finally, the temperature distribution has been obtained for porous nanostructure for different absorbed powers by solving the heat transfer equation.