The Miramichi Police Force say two people were rescued after their snowmobiles broke through the ice on the river Friday afternoon.
Police say that when first responders arrived, they found that two people had gone into the frigid water near the Morrissy Bridge.
They say the man had managed to get out of the water on his own, but that his wife had to be pulled out of the water by the first officer to arrive.
Both victims were transported to the hospital for treatment from hypothermia.
The rescue came at great risk to first responders, who had to wade through deep snow and water to make the rescue.
Both snowmobiles sank into the river where the water is around 10 metres deep.
The police are reminding snowmobilers to use caution on any ice surface.
The area in question is known to frequently have open water, even in January.