A woman was playing in the hot pools with her boyfriend at De Bretts Hot Springs near Taupo when she collapsed and was dragged out of the water by lifeguards.
The woman was taken to Taupo Hospital in a serious condition just after 8.15pm on Christmas Day, St John Northern Communications duty manager Ngaire Jones said.
De Bretts Spa Resort operations manager Mirela Petrar said the woman fainted in a pool, but staff reacted immediately.
"We had a lot of staff members on site. Some rostered on and others just having a swim which was a very quick response. It was really quick - like seconds.
She said the pool attendants pulled her out of the water.
