Not How it Works
Pneumonia is a very serious and sometimes life-threatening bacterial virus. Although you’re likely to catch it at least once in your life, it’s not as prevalent as the common cold. Sweating is something that can occur on a daily basis, especially in the summer. There’s no way it causes pneumonia, or else you’d have it all the time.

Was this mom just grossed out by her son’s pit stains, trying to freak her son out for amusement, or did she sincerely think sweat stains led to pneumonia? Often when sweat occurs, it is unavoidable. This guy, purely by living, figured out that his mom’s theory was total garbage.