Product manager Zenette Tan has been trained to perform CPR, use an automated external defibrillator and manage crowds of people.

The community volunteer with the People's Association's Community Emergency Response Team (Cert) is trained to respond to situations such as a terror attack.

"I wanted to be prepared... Every household needs somebody like this," said Ms Tan, 27, who became a Cert volunteer in 2014. "For example, my parents can't do CPR because they have knee problems, so if anything happens I can save them, or save my neighbours."

Learning basic first aid skills is a good first step to preparing yourself to react in a terror attack, she said.

There are more than 900 such Cert groups in Singapore, each with an average of 20 members.

Mentally rehearsing how to respond in an emergency also goes a long way, Ms Tan added. "People should mentally and physically prepare themselves to save someone's life. Anybody can be anybody's hero by just doing something that is within their limits."

Singapore has been stepping up efforts to equip people to deal with terror incidents, through its Let's Stand Together campaign and the SGSecure national movement. One of SGSecure's goals is to have at least one person in every household trained to respond to a crisis.

Associate Professor Kumar Ramakrishna of the S. Rajaratnam School of International Studies said being prepared can also help when travelling abroad. It is important for people to be aware of the latest security situation, news updates and national security advisories, as this would help them react in an attack.

"The basic message of 'run, hide, tell' is already out there," he said, citing the police advisory on what to do when caught in a terror attack. "The question is, when something happens, will we be able to respond?"

His advice for Singaporeans travelling abroad for the holidays is: "Have a plan, be aware of where the exits are, pay attention to the national advisories and be alert but not alarmed."