Can I rent a cell phone for the weekend?

I don’t have a cell phone but from time to time I drive out of town in the winter. I live in Toronto. I’m usually by myself and would feel safer if I had a cell phone in case of emergencies but I don’t want to go to the trouble of signing up for a phone I might only use once or twice a year. Is there such a thing as renting a phone for a short period of time?