I have read articles claiming that a fever is nature's way of combatting infection, and if you short circuit a fever by taking Tylenol or other drugs, you're really not helping your body.
Well, I had a fever for nearly two days and decided to take a Tylenol last night. It went from 101.9 degrees to 98.7 this morning. I was actually able to sleep, the hacking cough went away and I feel tremendously better.
So I am not sure I believe that theory.