I read the summary of the story, I think the title referred to a situation wherein a law must be rigidly implemented to maintain balance. There is no room for negotiation nor any changes in the fixed equation, to do so will result to catastrophic consequences.
The EDS where Marilyn stowed away contains fuel that is only good for a specific weight. Any excess weight must be jettisoned off the EDS to maintain balance. Regardless of any emotional turmoil that the law must produce, it must be observed. Thus, it is called a cold equation.
