"It would have only been a metre in diameter and it's not far from the river bank.
"When you look down into it it's like watery mud. It's bubbling so I would say it's boiling."
"Between her and her friends they really did the right thing. They recognised the seriousness of it got her out real quick and said to her, you need to get into the stream."
It is the second serious incident at a geothermal area in Rotorua in less than a year.
In December 8-year-old Toromon Toromon, fell into a pool at Rotorua's Kuirau Park.
He was burned all over his body, and died four days later in hospital.
When Mr Riedinger and other paramedics arrived at the scene the girl was still in the stream.
"She was laying up to her armpits in the cold water, which is absolutely the best thing she could have done.
"She's received some pretty serious burns, but I would suggest that if she hadn't have done that, it would have been a lot more serious."
The girl had severe burns to her legs and parts of her upper arms. She also had less serious burns on her lower body and torso.
"They've done well to get her in there. It certainly stopped any burns developing any further - which they could have done," Mr Riedinger said.
"She needed some pain management and was obviously very cold and wet. We had to get her out of the stream and she was in a lot of pain. We got her out onto a stretcher and had to carry her up the bank.
"Her mum met us at the scene. She's only an 11-year-old girl, so you see someone like that when they've got themselves into a whole lot of trouble it's always traumatic for the family."
Mr Riedinger said he could not speak highly enough of the effort to get the girl into cold water.
"They got onto it really smartly and did the right thing.
"It's not nice but it could have been a lot worse. If she'd been fully immersed [in the hot pool] I think it would have been a fairly poor outcome to be honest.
The girl was taken to Rotorua Hospital and later transferred to the burns unit at Auckland's Middlemore Hospital.
Last night she was in a stable condition.
Mr Reidinger said the area where she fell had many streams and hot and cold pools. But walkways and bridges were provided so people could walk safely past them.
"It's one of those areas that's open, where people go to have a look," he said.
"You just can't stop people getting near to areas like that."
