This study developed a numerical simulation of a hybrid microwave heating process that may be used to produce high heating rates for warming cryo-preserved biological tissue. A finite difference time domain (FDTD) technique was used to model the electric field distribution within a single-mode microwave cavity. Field strength data allowed power deposition to be computed and the control volume method was used to solve the energy equation. Temperature dependence of dielectric properties was simulated through an iterative process. As an illustrative example of the numerical model, a hybrid heating process was simulated. This simulation illustrated that hybrid heating schemes can be used to produce high rates of heating with increased uniformity of the temperature distribution and reduced incidences of local hot spots.