The 'Stay Put' Policy
The Stay Put policy is national guidance for residents of high rise buildings. The theory is that every individual flat within a block should act like a sealed compartment - able to contain a fire for at least one hour. If a fire breaks out in one flat, residents in other flats are advised to 'stay put' - to give firefighters enough time to get up the stairwell with their equipment and tackle the fire, without becoming blocked by residents evacuating down the stairs at the same time.
This is a very complex issue, as Pete Apps of Inside Housing explains in the article below.