From midnight tonight, all 999 medical emergency and unplanned medical admissions to Neath Port Talbot hospital will end.
These services will instead be transferred to Morriston, Singleton and the Princess of Wales hospitals.
Abertawe Bro Morgannwg health board says this is to ensure patients' safety because there's a shortage of suitably experienced doctors to run an Acute Medical Service.
The decision has led to strong opposition locally - but Abertawe Bro Morgannwg insists there are no plans to downgrade or close the hospital.
The Health Minister, Lesley Griffiths, has denied that Neath Port Talbot Hospital is being downgraded. Although she told AMs that the local health board is right to consider ending acute care at the hospital because it cannot recruit suitably qualified doctors.
Abertawe Bro Morgannwg Local Health Board is expected to go ahead with the proposal because it's been told that the hospital is not big enough to provide a suitable training environment for acute care doctors to develop their skills. Both the LHB and the minister deny that it's about saving money.