Industrial action by nurses has paralysed part of the health service in Northern Ireland in a dispute over pay and staffing levels.
The region has been without a devolved government for almost three years and there are no ministers in place to intervene. Thousands of medical surgeries and appointments have been cancelled.
Health trusts which run the NHS have said the 24-hour action by nurses was likely to result in "a significant risk to patient safety", but senior executives have said they are coping at present.
Royal College of Nursing (RCN) Northern Ireland director Pat Cullen said: "This is a day that no member of the RCN ever wished to see.
"The last thing that any nurse wants is to have to take industrial action."
RCN members are not striking but are refusing to do any task which is not "patient specific" because their pay has lagged behind that of colleagues in other parts of the UK.
The Belfast Health Trust, Northern Ireland's largest, cancelled more than 10,000 outpatient appointments and surgeries this week.
Ms Cullen added: "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, nurses have had enough."
The first day of strike action by RCN members is planned for the week before Christmas, on December 18.
On Monday night, the Unite trade union said its thousands of members in the health service had also voted to strike on December 18. The Unison union has also taken industrial action.
In the past, devolved ministers could reallocate money from other priorities and take key decisions on the transformation of the health service in the face of an ageing demographic.
This winter, none are in place due to the continuing fall out between former Stormont coalition partners the DUP and Sinn Fein.
Both parties say they want to re-enter powersharing as soon as possible, but a range of issues including the place of the Irish language in public services is preventing an accommodation.
Northern Ireland Secretary Julian Smith is to convene urgent powersharing talks later this month after the General Election.