A five-year-old boy is in a critical condition after a near drowning in a pool at a Hornsby residence this afternoon.

Bystanders administered CPR on the boy before NSW Ambulance paramedics arrived to provide treatment.

CareFlight’s Rapid Response Helicopter was tasked at 5:32pm and landed in Barker College.

CareFlight’s specialist doctor and NSW Ambulance critical care paramedic were escorted by NSW Police to the scene of the incident to provide additional treatment to the patient.

The boy was intubated to stabilise him by CareFlight’s specialist doctor and taken in a road ambulance to The Children’s Hospital at Westmead. He arrived at the hospital in a critical condition.