In college I heard insane stories from the nursing majors. Apparently going on shifts working 72+ hours non-stop is the norm. Imagine spending 72 hours in that hell: delivering this guy's meds, then checking this guy's blood pressure while he berates you, then typing in some paperwork, then giving this baby lab work while he's screaming, then doing more paperwork, etc. for 72 hours straight. I can't imagine it, I can barely imagine spending more than 3 hours.
Anecdotally, the few times I've been to doctors' offices and hospitals, I always notice the stress on doctors. Doctors and nurses are rushing everywhere, and they try to act nice but are simultaneously drained of emotion from disrespectful patients and general fatigue. Ironically sometimes they don't look that healthy, with all due respect, probably because of the immense stress and that it's hard to fit in exercise when you work 12-hour overnight shifts.
Also, I live in Massachusetts where hospitals haven't been near capacity for some time now. Everything I described is just regular operation, pre-Covid.