This work presents a novel direct estimation approach for the simultaneous identification of spatially variable thermal conductivity and thermal capacity in heterogeneous media. The fundamentals of the new methodology reside in the direct application of the integral transformed temperature measurements into the integral transformed heat conduction equation. The parameters that model the sought functions are then estimated with a simple minimization problem, which does not require the iterative execution of the direct problem solution, leading to a computationally fast procedure. The methodology is illustrated with some numerical examples representing different scenarios, demonstrating the feasibility and robustness of the approach.