The Greenlea Rescue Helicopter was called to a car crash on State Highway 41 at 8am on Monday 31 July.
A car rolled close to the highest point on the road the night before and the women driver lay trapped in the car overnight in freezing temputures.
She was found the following morning. The car was on its side and would have been hard to see from the road in the dark. The woman had to be cut out using cutting equipment.
She was flown to Waikato Hospital with serious injuries.