RCMP and Coast Guard volunteers rescued six people from a boat stalled on Prosperous Lake near Tartan Rapids.
In a news release, police said they were called just after 10:30pm on Tuesday.
"The boaters did not have any survival gear and were not dressed appropriately for the air and water temperature. Conditions at the time were dark and cold with temperatures below freezing," read the RCMP statement.
The rescue team found the stranded boaters and brought them to safety early on Wednesday. No serious injury or illness was reported.
Those on board the boat have not been identified – it's not clear if they were local to the NWT or visiting.
Police urged anyone out on the NWT's lakes or land "to be prepared for an emergency. Have a plan, practice water safety, and encourage others to do the same."