An experiment among U.S. soldiers halved the number of sick days. What was the experiment about?

Explanation

It is recommended that you wash your hands in the following situations: When you've got soil on your hands. Before you begin to cook. Every time you switch from one process to another while you cook. Before you eat. When you have been to the toilet. When you have helped others going to the toilet. After blowing your nose, sneezing or coughing. When you have put dirty clothes to wash. A study among U.S. soldiers who followed similar advice, halved the number of sick days.