Temple Street Hospital in Dublin is seeing an increase in a number of common winter infections, including the vomiting bug and whooping cough.
It is warning that these infections are usually mild in people outside of hospital, but can be severe if they spread among the sick children they treat.
Temple Street is encouraging parents to bring their children to their GP rather than the Emergency Department in the first instance, in order to help stem the rate of infection.
The hospital is also introducing temporary visiting restrictions - only parents and guardians of children in the hospital will be allowed to visit until further notice.