The importance of washing your hands

Why Do We Get Sick More Often During Winter?

It’s that time of year.  

Why do we get sick more often during the winter?
Why do we get sick more often during the winter?

In the news, in my newsfeed, and even in my own house, it’s easy to see that the flu and other illnesses are making the rounds.  In fact, many call this time of year “cold and flu season”.

Why is that?  

Many factors have been attributed to the predominance of viral illnesses during the winter months.

More time spent indoors in close proximity may increase the risk of person-to-person transmission.
The viruses responsible for the cold and flu survive longer in cold temperatures. 
Airborne aerosols (from coughs or sneezes) containing the viruses may travel farther and more quickly in the dryer air of winter.

Everyone has advice about how to protect yourself from getting sick: Take your vitamins. Spend more time outdoors in the sunshine and fresh air. Eat more fruit and vegetables. Exercise.  These are wonderful things that we should do, and all play a role in keeping us well.

But there is something even simpler that we can be doing to prevent illness.  In fact, it’s so simple that we may become lax about doing it well. What is it? Washing our hands.

Why is Hand Washing So Important?

According to one study, while 92% of surveyed Americans agreed that hand washing after using the bathroom was important, only 66% admitted to actually doing so.  For those who do regularly wash their hands, 70% of the survey participants reported that they’ve skipped the soap and just rinsed their hands with water instead.

I’ll wait here while you go vomit.

Additionally, the study showed that even those individuals who faithfully wash their hands may not be washing for long enough.  Many respondents indicated that they wash their hands for 15 seconds or less, shorter than the minimum 20 seconds recommended by the Centers for Disease Control (CDC). (For reference, 20 seconds is about the time it takes to sing the Happy Birthday song from beginning to end two times).

You should wash your hands using soap and water for at least 20 seconds.
You should wash your hands using soap and water for at least 20 seconds.

Why does it matter?

  • When done correctly, washing your hands (and proper hand hygiene) is the single most effective way to limit the spread of infectious diseases.
  • Germs can last more than 2 hours on any surface.  In fact, some viruses can survive for longer than 24 hours on a surface.
  • 50% of foodborne illnesses can be attributed to poor hygiene.  In other words, about half the time you are sick with a foodborne illness (a “stomach bug”), it’s because you’ve eaten something contaminated by someone else (often because they didn’t adequately wash their hands).
  • According to the CDC, if everyone routinely washed their hands, a million deaths per year could be prevented worldwide.

So hopefully by now you’re convinced of the importance of proper hand washing.  But how will you persuade your kids? Luckily, I’ve got two fun hands-on activities that illustrate the importance of washing hands.  These activities are appropriate for students of all ages.

Hands-on Activities for Teaching About the Importance of Hand Washing

Dirty Hands Bread Experiment

Here is an incredibly simple activity that yields impressive results.  The best part: you likely have everything you need to do this experiment right now.


  • 3 sealable sandwich bags
  • 3 pieces of bread (leave in the bread bag until you start the experiment)
  • One volunteer
  • Tongs (optional).  The point here is to avoid adding extra germs to the bread by touching it with your hands.  


  • Label your sandwich bags: control, unclean hands, clean hands
  • Using tongs, remove one piece of bread from the bread bag and immediately place in the sandwich bag labeled control. (Alternatively, you can turn your sandwich bag inside out and use it like a glove to pick up the piece of bread.  The key is to avoid adding germs from hands to the bread)
  • Remove a second piece of bread from the bread bag.  Have your volunteer touch both sides of the bread with their unwashed hands.  Then, place this piece of bread into the bag marked unclean.
  • Have your volunteer wash their hands with soap and water.  Remove a third piece of bread from the bread bag. Once again, have your volunteer touch both sides of the bread with their hands.  Place this piece of bread into the bag marked clean.
  • Leave the bags unsealed, but lay flat on the counter.  This will allow oxygen to enter the bags but will limit new germs from getting inside. 
  • Observe your bags each day and notice the differences you see.
Results from the dirty hands bread experiment. It's easy to see how important it is to wash your hands
Results from the dirty hands bread experiment. No noticeable growth was seen on either the control bread or the bread touched with freshly washed hands. In contrast, significant growth was seen on the bread touched with dirty hands.

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Here are the results from when my friend Kenzie did the dirty hands bread experiment with her kids. As you can see, there is no noticeable growth on the bread in the bags labeled control or clean. In contrast, there is a lot of mold growing on the bread in the bag marked unclean. I’ve seen similar results from others who have done this experiment and am always shocked at the differences seen when the bread is handled with clean and with unclean hands.

Some things to note if you plan to do this experiment:

  • Try to make sure that the volunteer spends the same length of time touching each piece of bread.
  • It makes a difference what type of bread you use.  Commercial white bread contains many preservatives, and consequently it can take a long time for growth to appear. Homemade bread or commercial organic bread gives faster results.

The growth that you see on the bread in the above picture is mold (a type of fungus).  Bacteria are so small that you’re unable to see their growth on bread (and viruses are even smaller than bacteria).  However, you can do a related experiment to test how well handwashing removes bacteria from hands using Petri dishes.

Directions for preparing Petri dishes as well as ideas for experiments to investigate hand washing and other fun topics can be found in this printable from my online Microbiology course.

Another fun way to demonstrate the importance of proper hand washing involves using Glo-Germ. 

Glo Germ Activity

What is Glo Germ?  

Glo Germ products contain plastic simulated germs that glow under black light.  To use, simply apply Glo Germ to hands and allow to dry. Then, wash hands as you would normally.  Following hand washing, examine your hands in a dark room using a black light. Any spots you missed will glow.  The results are illuminating to say the least.

Ways to Use Glo Germ

I have used Glo Germ for years, both at home and in classroom settings.  Students of all ages (even high school/college students and adults) are shocked by the results.

Using Glo Germ at Home

At home, you can squirt a small amount of Glo Germ on your hands and rub it in. Use your UV light in a dark room to examine the glowing Glo Germ on your hands.

Next, wash your hands using soap and water the way you normally do. (This works best to measure how well you wash your hands if you don’t change the way you wash your hands). Then use your UV light to see if all of the Glo Germ has been removed.

Using Glo Germ is even more fun in a classroom setting.

Using Glo Germ in a Classroom

When using Glo Germ in a class setting, I typically start the day by squirting a small amount of Glo Germ in the hand of each student and asking them to rub it in on their hands. I don’t tell the students what they’ve just rubbed in, but most guess that it is lotion or hand sanitizer. (I cover the label of the Glo Germ bottle with tape to keep clever kids from figuring out that they are part of an experiment).I then let students go about their day.

After several hours (preferably after they’ve eaten a meal or have had time to use the bathroom), I turn off the room lights and turn on the UV light. I go throughout the room with the UV light, checking students’ hands. Presumably, since students should have washed their hands before eating and after using the bathroom, their hands should have