With increased power density, chip temperature has been increasing steadily, resulting in several adverse effects. The most pronounced effect is the increase in leakage power. Leakage power is strongly dependent on temperature. Increase in leakage power further increases the on-chip temperature, resulting in a feedback effect. While there has been a significant amount of research in the area of fast thermal simulators there is hardly any research that focuses on fast leakage aware thermal simulators. Our goal is to propose a leakage aware thermal simulator for 3D chips that is fast enough for runtime applications. Also, it should be able to model fluid carrying microchannels. We have used algebraic and transform based techniques in Green's function based approaches to achieve a speed up of 70X over state of the art simulators. Currently we are working on modeling fluid carrying microchannels.