Ever read that sign in the elevator that tells you to take the stairs in an emergency?

That may be a mistake according to the 162-nation International Organisation for Standardisation, which said using lifts can sometimes save more lives as people rush out of buildings after fires, earthquakes and gas explosions.

The ISO, which sets international standards for everything from screw sizes to ripening fruit, said in a report that elevators are an increasingly viable escape option as buildings get taller.

It said Wednesday that building designers should consider various elements when deciding on emergency exits. Not least, how to save the lives of people who can’t use stairs such as the disabled, elderly, pregnant women and small children.