The HSE says the healthcare system is overheated and under serious pressure.
It comes as the Cabinet Sub Committee on Covid-19 will meet this evening to consider what action needs to be taken to tackle the escalating covid-19 cases.
According to latest figures 13 patients are being treated for Covid at Sligo University Hospital and 19 at Letterkenny University Hospital.
NMO members at Mayo University Hospital will protest outside the hospital this afternoon, to highlight excessive workloads and staffing pressure.
The union says staff in the hospital are unable to take adequate breaks or use their annual leave due to their excessive workloads.
Formal grievances have been brought by staff and the union to the Saolta group, which operates the hospital.
Chief Clinical Officer with the HSE Dr Colm Henry says staff had to provide critical care outside ICU in certain hospitals settings over the weekend.
