When two (or more) people in an apartment building happen to try and take hot showers at the same time, quickly draining the building's hot water.
Matters escalate when they realize that the water is getting colder faster than normal. They begin to slowly turn their hot water up in an effort to stay comfortable. It becomes a race when both parties try to finish their showers as fast as possible.
One of the sorority girls downstairs and I got into a Cold War this morning as I was getting ready for work and she was probably washing the shame off from Ladies Night.