Toronto Fire crews were called to an apartment building near Dundas Street and Sherbourne Street at around 5:20a.m. Thursday.
The fire broke out in a seventh floor unit. One tenant inside the unit was taken to hospital for smoke inhalation and minor burns. A security guard was also treated at the scene for smoke inhalation.
It was believed that the fire was caused by careless smoking.
The building did not have to be evacuated.