Do you smell something funny? Not on an airplane, I hope, because many carriers have rules about odors.
If this sounds crazy, do what I did and read your airline"s fine print. You"ll find it in the dense legalese of the "contract of carriage" located on most carriers" websites. What it boils down to is the various conditions under which airlines agree to carry you and your belongings, and when they will refuse you.
Some of this is pretty serious stuff; some will strike you as utterly absurd. I've got examples of both and don't miss No. 13 - my nominee for the Captain Obvious award.