Here's Why It's So Hard to Achieve the Perfect Temperature While Taking a Shower

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The only thing worse than stepping out of a warm shower into a chilly bathroom is owning a shower that seems to only have two temperatures—scalding or freezing—unless the knob is positioned just so. Curious as to why it’s so hard to achieve bathing nirvana with a simple twist of the wrist? In the video below, SciShow host Stefan Chin broke down the intricacies of home plumbing, and offered advice on how to keep your shower from going from blissfully warm to bitingly cold.

With home water heaters, “adding really hot water to cold water changes the temperature more than adding the same amount of water that’s just warm,” Chin explains. “So if the water is too hot, tiny changes in how much hot water is sent your way can lead to big changes in the temperature of the mixed water hitting your body.”

And “the water in water heaters is usually very hot,” he adds. “It’s generally set to around 50°C [about 122°F] to kill bacteria.”

Meanwhile, some small water heaters simply don’t hold enough hot water at any one time for a long shower—plus, lots of plumbing simply isn’t designed to check the temperature of the hot-cold water balance.

A hot shower is perhaps the simplest—yet most universal—luxury you can enjoy, so you probably don’t want to waste your precious relaxing time fiddling with the dial. (Plus, some creative types find that their best ideas often emerge when they’re relaxed and sudsed up—something that can't really happen when you're being doused with cold water.) Rest assured, Chin has some shower solutions, which you can learn by watching the video below.