The group say St Patrick's Day is always a very busy day for EDs and say people with less urgent needs may face extremely long delays.
Over 28,300 people attended an Irish Emergency Department last week, which the HSE says is the highest figure ever recorded.
People are being asked to contact local injury units, their GP or local pharmacy if their needs are not urgent.
Meanwhile, visiting restrictions remain in place at Bantry General Hospital.
All elective surgery has been cancelled and visiting will only be allowed on compassionate grounds.
