Or as we use to say in the Army. How to keep your shit together!
Now I know this is a yucky subject. But if one ignores taking care of business in the field. You and others can & will get quickly very sick or die. No kidding!
Because before WWI. Most soldiers died from disease not from Bullets, Bayonets etc etc. That is why today the Military is very fanatical about cleanliness & for good reason.