Nurses in Northern Ireland are taking part in a second day of their latest industrial action.
The Royal College of Nursing is pressing for pay parity with colleagues in the rest of the UK and for improved staffing levels.
This 48-hour action will see nurses working strictly to their contracts, including taking breaks.
On Tuesday, it emerged paramedics will join strike action for 24 hours on Wednesday 18 December.
The RCN Northern Ireland has issued a list of services that will be exempt from next Wednesday's planned strike action by health unions.
They include chemotherapy inpatient and outpatient services, units providing palliative care, psychiatric intensive care units and intensive care units.
Emergency Departments will not be exempt but life saving cover will be provided, the RCN added.
The list has been given to its members, health and social care employers and the Department of Health.
'Point of collapse'
Members of Unison - Northern Ireland's NI's largest health workers' union - are engaged in ongoing strike action.
The Belfast Health Trust said all hospital surgical procedures, inpatients and day cases and all outpatient appointments will proceed as normal on Wednesday, except for outpatient appointments in the School of Dentistry.
The Northern Trust says some routine appointments at the Causeway Hospital will be affected, while some services in the Western Trust will also be affected.
The latest information can be found on the Health and Social Care Board website.
The Royal College of Nursing's programme of industrial action began at the start of the December.
It is the first time in the union's 103-history that members voted to take such action.
The RCN said it had about 16,000 members in Northern Ireland, where some 17,000 nurses and 5,000 nursing support workers are employed in total.
Nurses are refusing to do things like working overtime shifts, working unpaid hours and answering phones on wards.
RCN Northern Ireland director Pat Cullen said nurses felt they had no choice but to take action.
"With around 2,800 vacant nursing posts in the system, record levels of expenditure on agency staff to try to plug the gaps, and nurses' pay continuing to fall further and further behind the rest of the UK, nursing staff have had enough," she said.
Health workers have said they are unhappy about pay and claim staffing levels are "unsafe".
The Royal College of Surgeons warned last month that Northern Ireland's healthcare system was "at the point of collapse".
Unions rejected a new pay offer by the Department of Health last week because it did not reach parity with staff in England.