Experimental results play a crucial role in the validation of mathematical and numerical models for a variety of thermal transport problems. Material properties that are crucial to any accurate simulation are obtained experimentally. In addition, there are many important processes where the boundary conditions are not well defined. However, experimental work can be used to provide the appropriate boundary conditions, or the numerical solution of a coupled inverse problem can be used to define these for an accurate simulation. Finally, there are many problems in which numerical simulation is particularly suitable over given parametric ranges, while experimentation is more appropriate over other regions. In such cases, a concurrent numerical and experimental approach may be used to solve the problem more accurately and efficiently. The basic considerations that arise in these approaches are outlined. A few circumstances, where a coupling of the experimentation with the simulation is appropriate, or where experimentation is used to define the boundary conditions are presented.