Police, St John Ambulance from Ruatoria, the Tokomaru Bay volunteer fire brigade and the ECT rescue helicopter responded to the emergency.
"Attempts were made to resuscitate the boy but he could not be revived," police said.
"We can confirm the boy was under specialist care for a medical condition."
The boy's body was flown to Gisborne Hospital by the ECT Rescue Helicopter.
The chopper was also used to fly the boy's father, a forestry worker, to join other grieving family members at the school.
Victim Support services have been offered to the family.
Police have an inquiry under way into the tragedy on behalf of the coroner.