A nanometer is defined as one-billionth of a meter. At these minute scales the materials behave remarkably different than their counterparts at higher dimensions. The advancements in the field of Nanotechnology and Nanofluids have triggered an interest in the heat transport that takes place at these nanoscale levels since it is unknown whether the existing macroscale heat transfer theories can be used. The Cattaneo-Vernotte (CV) constitutive model for nanoscale heat treansfer which is based on the correction made to the assumption of infinite speed of heat propagation proposed in Fourier law, involves solving using complex numerical procedures. A new model is presented in this book called the nanoscale lumped capacitance model that gives a simple closed form solution to nanoscale heat transfer problems by modifying Cattaneo-Vernotte (CV) constitutive relation.