Treato found 16 discussions about Cold Symptoms and Cats Allergy on the web.
Best Answer: When the toilet is flushed, the toilet is robbing pressure from the shower, which is usually close to the toilet. As the COLD water pressure goes down from the toilet flush, the HOT water pressure is higher, therefore the water gets hotter as the COLD pressure goes down.
Finally I had to know. Why does flushing a toilet make the shower run hot? Luckily, a quick search turned up the explanation on Yahoo Answers: The same water supply feeds both the toilet and the shower. So when the toilet flushes, it uses all the cold water to refill its tank and leaves nothing for the shower. The problem can be caused by using cold water from any appliance. Kitchen sinks, washing machines, and sprinklers are all liable to steal away the cold water and leave you screaming.