Although they are both "science," I think it is hard to make a good comparison because of the immense body of knowledge in medical school that I mentioned above. If you did AP Chemistry in a week or two you wouldn't cover an unreasonable number of memorizable facts, but you would cover more new principles requiring complex conceptual understanding than you would in a week of medical school. Personally, I think the concepts covered in many college courses (physical chemistry, electrical engineering, and literary theory were tough ones in my experience) are much more difficult to comprehend and master than those of medical school. If you can wrap your mind around AP Physics, you should be able to master, with effort, the most complex aspects of medical school physiology, pharmacokinetics, or immunology.
I think the closest comparison would be to imagine taking AP US History, European History, and Physics simultaneously over 6-8 weeks. You would be learning and applying many new and tricky concepts, but the bulk of your long study days would be filled with the learning, review, and memorization of thousands of regurgitable facts.