If you’re like me, you grew up with your parents telling you to make the water as hot as you can stand it before washing your hands.
Well, it turns out all that talk about hot water is hot air.
Researchers have published studies that indicate the germ-killing effects of soap have just as much of an impact with cold water as they do with hot water. And what’s more, using warm water each time you wash your hands wastes a lot of energy.
Washing with hot water actually has a lot of negatives.
For instance, using hot water each time hands are washed can irritate skin and cause your hands to dry out. When the skin becomes dry, it can become less useful as a protective barrier against bacteria.
According to one researcher featured in this National Geographic article, people use hot water about 60% of the time when washing their hands.
Because Americans wash their hands over 800 billion times a year, more than 6 million metric tons of CO2 are released into the atmosphere each year. That’s about the same emissions as from two coal power plants or 1.2 million vehicles driving for a year!
These researchers indicate that if we Americans can simply stop using hot water when washing our hands, we can make a significant impact on energy usage and CO2 emissions.
What the Rest of the World Thinks
I asked my wife about this (she’s not American) and she started to laugh and said, “You didn’t know that? Everyone knows that.”
In a study published in the July 2013 issue of the International Journal of Consumer Studies, 510 American adults were interviewed about their hand washing habits.
Close to 70% said that they believe using hot water was more effective than just water and soap, even though there is no evidence that hot water improves the effectiveness of hand washing. (See, we’re not alone)
One of the lead investigators for the study, Amanda R. Carrico, said that …
some people may have a negative reaction. With any change, you are going to have some small backlash effect, but most often it is not going to make up for the benefits that come from broader public education.
Over to You
How do you wash your hands? Do you use warm or hot water? Do you think there’s an added benefit to educating the world on the facts of water temperature in hand washing?
