The incident happened in January 2014 on a day when temperatures hovered around –35 C.
Cellphone video posted to YouTube by a passerby shows officer Pierre-Luc Gauthier reprimanding a disheveled man who had been asking people for change. The man was dressed only in shorts and a T-shirt.
The officer tells the man he has to calm down and find a place to warm up. Then he tells the man he will tie him to a pole for an hour if he gets another complaint about his panhandling.
In its decision released Monday, the tribunal ruled Gauthier's threat was "excessive" and an "abuse of authority," regardless of his motivation.
Gauthier's partner, Vincent Marcotte, was also reprimanded for not stepping in to intervene.