If an investigator has Vessel of the Mythos and is reduced to 0 stamina, what happens? The card says he can't enter stable locations. Does that mean the investigator can't be sent to the hospital and be restored to 1 stamina? Or does being barred from stable locations (and hence the hospital) mean the investigator can't enter as a move action, but can be sent there? So in effect, he's sent to the hospital, but can't walk in during movement?

Going insane or unconscious always sends you to the Hospital/Asylum, even if you can't enter that space voluntarily. Otherwise there would be no place to put your character when s/he went insane/unconscious.

Okay, thanks for the clarification.