Before they reach the pick-up areas in housing estates, clinics and the airport, the medics from Civic Ambulance switch off their sirens and drive as silently as they can. They try to park in an obscure corner.

This is one lesson picked up from the Sars period in 2003 to prevent unnecessary paranoia, said Civic's operations director Prithpal Singh. It was then that the company was first roped in to handle calls to the 993 hotline.

Read the full story in Saturday's edition of The Straits Times.