The context
Hospitals depend on equipment that most people never think of as thermodynamics. An MRI scanner relies on cooling to run, cold rooms must hold their temperature without exception, and heating has to stay stable in places where people are at their most vulnerable. This is exactly our trade, and it is why we are called in: the physics are the same as for a heat pump or a cold room, only the stakes are higher. These machines do not tolerate approximation. After a few operating cycles every setting has to be checked again, because a small drift that nobody sees today becomes a stoppage tomorrow.
