In 1822, Fourier used empirical data to produce a groundbreaking treatise, in which it is stated that the rate of heat transfer through a material is proportional to the negative temperature gradient. For different materials, the resistance to this heat transfer varies, which is why the rabbit in the picture above emits more heat through its eyes and ears than through its fur. In this exercise, some conceptual insights about the application of Fourier’s Law will be tested. No calculations are required yet.