The emergency department at the St. Marys Memorial Hospital will be closed overnight on Thursday.
The Huron Perth Healthcare Alliance said the ER closure is a result of "health human resource shortages."
The department will close at 5 p.m. and reopen Friday morning at 7 a.m.
Anyone requiring immediate medical attention should call 9-1-1 and they'll be rerouted to the nearest available hospital.
The closest 24-hour emergency departments to St. Marys are Stratford, Exeter, Ingersoll and London.