A man has been thrown head over heels 50m down the side of Mount Ngauruhoe after he was struck by a falling rock.
The Greenlea Rescue Helicopter had to use a long line to rescue the tramper from the mountainside yesterday.
He was subsequently flown to Rotorua Hospital for treatment.
The Department of Conservation warned trampers to be aware of falling rocks on the steep volcanic slopes, which could be dislodged by other trampers further up.
It said people should also take care because it was easy to trip and fall on the rugged loose rock surface.