Has the creator of this (an excellent) game ever taken a shower?
Don't worry, it's a joke, but I can't stop myself from doing it.
So if you have the unfortunate idea to flush the toilet, the toilet will therefore refill.
However, until proven otherwise, the flush is filled with water ............ COLD!
This means that, for those who have the unfortunate idea to take a shower at the same time, because there will be less pressure in the COLD water, the temperature of the shower water will inevitably INCREASE, and that the person(s) in the shower at that time will feel at least a feeling of HEAT or even possibly BURN themselves.
So to say that the shower is going to cool down suddenly implies that those who argue this theory either live alone or may have never taken a shower... or are going to pee in the garden.