I think physicians are for the most part more than willing to let students shadow them for a while. Provided you dont distract them too much from their work and that you don't shadow them for an unusually long time. Just get a feel for what they do and once you're pretty familiar and its routine, you dont learn much by continuing. If you have some contact it helps, but if you just tell them about your vested interest, they'll understand. Being considerate usually comes with the profession.