In the new movie "Bringing Out The Dead" starring Nicolas Cage, Martin Scorsese (also the director of the movie) in the scene where Nicolas Cage brings in a patient to the ER, the ER nurse uses a rectal thermometer to take an oral temperature. You can tell the difference in thermometers as, oral thermometers are blue ended, and rectal are red..
If it was the Misery hospital (i can't remember), that may have been intentional just to emphasize on how hectic and unorganized it was. Then again it might just be a slipup!