Going to a dentist for a tooth that needs a root canal...

See, the thing is, they need to make sure they have the right tooth. The right tooth will be infected and have extra sensitivity. In order to probe for the right tooth, the spray a blast of this ice cold solution (think gum remover, compressed air) on a couple of your teeth. The tooth that illicits the right response (you damn near jumping out of your chair and ready to punch the nurse) is the right tooth.

This little experience will bring you back to earth QUICK FAST!