Breaking out any windows during a fire is something you should NOT do! It can make the fire much worse and decrease the chances of survival for trapped occupants if not done correctly.
When firefighters break out windows during a fire, they are using a scientific approach, learned during extensive training, to extinguishing the fire. Windows are broken in coordination with firefighters on the inside extinguishing the fire to create an escape route for the superheated steam and gases to escape. Without the windows being removed, the steam could burn the firefighters and hinder rescue efforts of any trapped victims.