Why is Jim naked at the hospital

yes...also looters would have stolen his clothes

Or maybe he was naked and covered by a blanket and during the chaos while he was in a coma the blanket got pulled off him.

Idk but I would have been woundering why I was nude

I'm sure that was the least of his concerns after waking up.

If you've ever been in the hospital, it makes sense. When you enter the hospital during an emergency, the first thing they do is cut off your clothes to give you a thorough exam. Only after they stabilize a patient do they dress them and take them to a room.

There are several explanations as to why he was nude. It is entirely possible they were in the middle of admitting him or working on him at the time the hospital was overrun. That, or in the chaos, they never got around to getting him in a hospital gown. Or, since this was around the time when the virus first presented, it was to prevent contamination or infection from the virus, since they wouldn't know how it was spread at first.

I see it as just being too chaotic in the hospital to bother getting him dressed. They simply had too much else to worry about. I have no idea why you would think a doctor at that time would have the thought/time/focus to be raping patients while the city imploded into death and chaos.

I always interpreted Jim being naked as symbol of his rebirth. He wakes up from almost dying into a new world, his eyes open and the white light enters the room. The set up all felt quite clinical and unnatural at first, that's why I never took the reason for his nudity as being literal. But maybe that's just me, I probably think too much.

Maybe they were preparing to give him a sponge bath?