During Mr Lim Zi Yao's course of work as a legal counsel for a hotel chain, national security is often not at the top of his mind.

But in the past year, the 30-year-old has become more sensitive to the threat of terrorism here, and the need to be prepared in the event of an attack - since he was roped in as an SGSecure mobiliser in July last year.

The Singapore Civil Defence Force (SCDF) national serviceman was among the pioneer batch of officers who went door-to-door in the heartland to raise awareness of the national movement.

Together with the rest of his team from the Public Shelter and Resilience Unit, Mr Lim covers between 10 and 15 HDB blocks in an afternoon.

During their visit, the team members introduced the various mobile apps developed by the Home Team agencies. To familiarise residents with the equipment, they would bring along a small fire extinguisher and an automated external defibrillator (AED), a device that delivers an electric shock through the chest to the heart.

"I was surprised to learn that many residents were willing to listen and find out how they can better equip themselves with life-saving skills," said Mr Lim, who works at Four Seasons Hotels and Resorts.

"Some have heard of an AED, but they have not seen one before. If they can identify it, they can also play a role in getting the AED in an emergency."

He also reminds residents about the need to boost their "psychological readiness" by keeping them abreast of local and international news. Mr Lim also shares all this information with friends and colleagues.

One such opportunity was when a minute-long siren was sounded across the island through the Public Warning System siren network on Sept 15. A few colleagues, who were hearing it for the first time, asked him questions. "I find that even in daily conversations, there is a chance to share messages on readiness."

Ng Huiwen