However, if the situation is not life-threatening but still requires treatment, NHS Lothian will arrange for the youngster and the parents to be transferred from the new Royal Hospital for Sick Children and Young People in Little France to the Sick Kids hospital in Sciennes.
In the meantime, parents are being advised to continue using the existing accident and emergency department at Sciennes.
The new hospital was due to open next Tuesday but a sudden announcement on Thursday afternoon was issued saying health secretary Jeane Freeman had decided to delay its opening after problems had been identified with the ventilation system in the critical care unit.
An investigation is now under way.
NHS Lothian has also issued an apology to parents over the confusion caused by the change of plan and is publicising a helpline number to answer questions on dates for appointments.
Jacquie Campbell, chief officer of acute services, NHS Lothian, said: “I would like to apologise to patients who may be confused and worried about the plans for their care and reassure them that we have a raft of contingency plans in place.
“The most critical point is that accident and emergency will not move. In an emergency, patients should still take their children to the building in Sciennes.
“Patients who have an appointment scheduled in the new building will be contacted by their team either at the existing Royal Hospital for Sick Children or the Western General Hospital to arrange an alternative location and every effort will be made to retain the same date and time, if possible.
“We have a dedicated helpline in place to answer any questions and concerns that patients may have about their forthcoming appointment.”
The dedicated helpline number is 0800 028 2816. It is open 8am to 10pm Monday to Friday and 9am to 5pm on Saturday and Sunday.
This includes those due to attend the department of clinical neurosciences which was also set to move to the new hospital.
Thomas Waterson, chair of Unison Scotland’s health committee, said the latest arrangements had been issued at a time when the hospital was “in chaos.”
“We’ve got people phoning parents whose children have appointments at the new hospital telling them not to turn up at Little France but to go to Sciennes.
“It’s the same situation with staff not knowing where to go.
“But the decision has been made by the health secretary”.
Mr Waterson added: “It is an inconvenience to parents but to be fair it is similar to what they did when they opened the new Edinburgh Royal Infirmary.”