Every time anyone says 'Iris', their lip movement doesn't match.
When Vincent is listening to the young girl's lungs, he only listens in one spot and tells her to breathe in while the thermometer is in her mouth. The lungs have multiple lobes, and therefore doctors need to listen to various spots, both front and back, to get a more accurate idea of possible illness. A patient would not perform deep breathing necessary for a lung exam with a thermometer in their mouths.