is a kind of step down E.R. Sometimes they are private and sometimes physicians services use them to cover their patients for unscheduled visits . I worked at one that was staffed by the M.Ds of the service who rotated service. It kept the general practitioners current in things like suturing , anaphalaxis and broken bone emergencies and allowed people who had painful problems like UTI or sore throats. to receive treatment quickly . We gave IV fluids for excessive vomiting and had a lab to check for strep, etc.
Chest pain that looked serious was sent to a hospital in an ambulance. It was a walk in clinic rare and people rarely had to wait longer than 1 hour.People's visit records were sent to their M.D. and a follow up appt was made before they left.

We need more of these.