It's following a case of Coronavirus at the hospital
Staff are being redeployed, while visitor restrictions are in place and elective procedures are being curtailed.
Yesterday, the first case of community transmission was confirmed, when a man in his 40's who had been treated at CUH was found to have Covid 19.
The number of new cases in the Republic doubled last night, and now stands at 13.
Guidance about mass gatherings such as sporting events and St. Patrick's Day parades is expected to be published today however a decision has already been taken to cancel the Youghal St Patrick's Day parade.
Dr. Chris Luke, a former consultant in emergency medicine at CUH, says tough decisions are going to have to be made in hospitals: