  Energy loss through optically thin radiative cooling plays an important part
in the evolution of astrophysical gas dynamics and should therefore be
considered a necessary element in any numerical simulation. Although the
addition of this physical process to the equations of hydrodynamics is
straightforward, it does create numerical challenges that have to be overcome
in order to ensure the physical correctness of the simulation. First, the
cooling has to be treated (semi-)implicitly, owing to the discrepancies between
the cooling timescale and the typical timesteps of the simulation. Secondly,
because of its dependence on a tabulated cooling curve, the introduction of
radiative cooling creates the necessity for an interpolation scheme. In
particular, we will argue that the addition of radiative cooling to a numerical
simulation creates the need for extremely high resolution, which can only be
fully met through the use of adaptive mesh refinement.
