Besides the reality of the arrival of eager new medical students and interns (the first week of July, as Dr. Oz mentions), teaching hospitals, like many industries, have employees who take vacation time during the summer months. And summer vacation time is often awarded to the more 'senior' staff people, those with the most experience and the most time on the staff. That includes physicians, nurses, physical therapists, radiology technicians, orderlies, et al. So not only are there spankin' brand new interns and residents wandering the halls, there may be less experienced staff in the hospital to do the studies and the procedures that you need.
As with anytime you are being seen as a patient in the healthcare system, you do need to be an empowered patient---asking questions, making sure that you are getting the appropriate medication or study, and generally doing what you would do even if it wasn't July 5th.
Don't panic, though, if you do need to be hospitalized in the summer. There are plenty of caring, engaged staff who will be there as well.
I smiled when I read Dr. Oz's answer to this question. He does a great job of describing the new medical students and interns arriving. As a Professor who teaches these new doctors, Dr. Oz knows what it is like to have new students and physicians. It is also a time when the Professors (like Dr. Oz) and seasoned nursing staff make sure that patients are well-cared for.
If you are a patient, understand what happens during this period of time, ask questions, and request to talk to the attending physician and/or the charge nurse if you have any concerns. It is a busy time but the patient should always be the focus.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.