This article describes a feature in the first Apocalypse Rising
Clinics are smaller hospitals which usually spawn about a total of 12 blood bags, food, drinks, and painkillers. Some clinics have windows in the back of them. There are also 2 rooms in the clinic, a main room with a counter and a back room. They are very useful if you are being chased since there are lots of blood bags and a small room you can ambush them from. Just make sure you don't get trapped in there when ambushing people. You could make your own pharmacy in one too, if you'd like.
There are clinics in Kin, Mason, and Dirk. On the map, they are identified by a plain Red Cross(for Reimagined and Amend). Hospital(s) have a white square around a red cross and have multiple windows.