Using heat maps provides frame and relevance to topics covered in physical acoustics courses as students can more easily visualize complex ideas and situations. Students can also form a much better understanding of the physical phenomena involved and build more advanced critical thinking when heat maps are used. It is the aim of the paper to provide ways for students to interact with heat maps by using two examples: first, the interaction of a plane wave (not only monochromatic) with an interface separating a fluid and a solid medium and, second, the interaction of an acoustic beam with such an interface (including a solid layer). These heat maps permit both to describe non-specular effects for the reflected acoustic beam due to the generation of a modal wave and, in the case of anisotropic media, highlight the difference between the direction predicted by Snell-Descartes law and that predicted by energy flux.