A Ngaruawahia firefighter has rescued a girl who was clinging to a support pile for a bridge on the Waikato River this afternoon.
Emergency services were called after the girl got into trouble at the main road bridge in the town at about midday.
Fire and Emergency said the girl was very cold, so it was decided not to wait for a rescue boat and a firefighter swam out to her.
The officer, described as an "excellent swimmer", donned a lifejacket and took another to the girl.
The two then made it back to shore further downstream.
The girl was taken to Waikato Hospital in a serious condition.