Companies were dispatched for the working dwelling fire with heavy smoke from the 3rd floor of a 3 story twin. Ladder-3 arrived and stretched a 2" handline to the 3rd floor. Interior crews experienced heavy smoke and heat conditions but made a quick knock on the fire, while exterior crews went to the roof to vent. F/F's also enterd the exposure dwelling to vent heavy smoke from that side of the bldg. Fire was held to the front bedroom of the original fire dwelling.