One of the most major breakthroughs in preventing the spread of illnesses and infections in hospitals was embarrassingly simple. Wash your hands. In 1846, Hungarian physician Ignaz Semmelweis discovered that hand washing played a vital role in the spread of germs, and the practice soon became mandatory in hospitals. The simple act of scrubbing hands with soap and water literally saved lives.
Getting a kid to wash their hands, however, can be an uphill battle. One teacher did a simple experiment to show her students just how important hand washing is.