In order to simulate the hyperthermia cancer therapy in multilayer skin, a solution for Pennes’ bioheat transfer equation based on the strongly continuous semigroups, domain decomposition technique, Laplace transform and numerical inversion of Laplace transform is proposed. In the existence of a tumor, solution at the presence of internal heat source and surface cooling temperature is considered. This solution considers both Dirichlet (body core condition) and Neumann (surface cooling condition) type boundary conditions. The interface conditions for a multilayer problem are derived from the corresponded eigenvalue–eigenfunction formulation of infinitesimal generators. It is proved that an infinitesimal generator is Riesz spectral operator and the corresponding system is exponentially stable. By two work examples, numerical results for hyperthermia cancer therapy in the existence of a tumor are presented.