Washing your hands in hot water is, according to one Vanderbilt researcher, a pretty useless endeavor.

Here’s what it is doing:

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  • Creating, in total, as much carbon emissions as the whole of Barbados
  • Drying out your hands.

Here’s what it’s not doing:

  • Killing any germs.

As Amanda Carrico explains to National Geographic, sure, hot water can kill bacteria, but it has to be so hot that it would scald your skin. We’re betting that water you’re using isn’t that hot. (And if it is, ouch! Sorry about your hands.)

There’s a pretty simple alternative: Use cold water, but wash your hands for more than five seconds — do the whole “soap and water and scrubbing vigorously, for at least 20 seconds” thing. And then dry your hands, and use them to pat yourself on the back for saving energy.