A man has been airlifted to hospital after an accident involving a nail gun in Sydney's north-west.
The 36-year-old is understood to have been shot in the chest while helping a friend on a renovation project at Freemans Reach.
CareFlight's rapid response chopper was tasked just after 3pm.
It landed in the grounds of Hawkesbury High School across the road.
Police and NSW Ambulance were also at the scene.
The nail caused an injury below the sternum.
He is currently in a stable condition.