Do not attempt to extinguish the fire yourself unless you have received portable fire extinguisher training and are a company fire warden or member of an emergency squad. Even if you are a fire warden, your main duty is to signal the existence of a fire and evacuate, so only tackle the fire if it is small.
Close windows, if this can be done swiftly and without jeopardising your safe evacuation.
Leave the area quickly, closing the door.
Raise the alarm at the earliest possible opportunity by triggering a manual call point.
You should then follow the emergency evacuation procedures for fire alarms.