The very common situation of waiting for the cooling of a cup of coffee is addressed through a conventional engineering approach, where several important concepts of heat and mass transfer are used. A numerical and analytical solution of the differential equations of the problem are proposed, and assessed by comparing to simple experiments. Numerical resolution was done using the Mathcad[R] software. Results predicted by the model, which contains no adjustable constants, agree very well with experiment. (Contains 2 tables and 4 figures.)