Dressed in yellow vests and bright red shirts, Madam Liew Yin Wan and her daughter, Ms Koh Suan Tian, stand out in their grey Sengkang neighbourhood.
They are the area's resident "dengue fighters" - volunteers who go from door to door encouraging their neighbours to keep up the fight against dengue.
Unlike officers from the National Environment Agency (NEA), they do not inspect people's homes for potential mosquito breeding grounds. Instead, they try to spread the word in as friendly a manner as possible.
"It's not like a lecture," said Ms Koh, 34, who works as a quality manager in the healthcare industry. "We're not here to give you the fliers and say: 'That's it, my duty is done.'"
In the hour that The Straits Times tagged along on their visits on Monday evening, the volunteers rarely knocked on closed doors or called on people who were obviously busy.
Conversations that they struck up with residents, however, lasted at least 10 minutes and went beyond simply reciting a list of dengue prevention tips.
Instead, they tried to tailor their message to what they observed about people's lifestyles.
Those with water plants, for instance, might be reminded to wash the roots as well, as mosquito eggs might stick to them even if water is changed regularly.
A family with young children might be asked to keep toilet bowls covered before they go overseas for the March holidays.
"We try and highlight to people the key points that they need to take note of, and tell them things that they might not know," said Madam Liew, 70.
The mother-daughter pair joined the Community Emergency Response Team (Cert) in the 1990s, when it was still being run by the Singapore Civil Defence Force and went by another name. There, they learnt skills such as first aid and basic firefighting.
In 2014 - about a decade after the People's Association took over the management of the team - they were roped in to help stop the spread of dengue in their neighbourhood.
Madam Liew noted that residents generally seem more aware of dengue and its potential impact nowadays. "When we first started out, not many people knew about (dengue) and they didn't know the danger. Now people are more aware."
There are currently nearly 6,000 such grassroots volunteers, with plans to recruit and train another 5,000 more as part of efforts to step up public education.
The hope is that people will be more receptive to such volunteers, who are neighbourhood residents themselves and hence likely to be familiar faces.
As many volunteers have full-time jobs, they make house visits on weekday nights or weekend mornings, typically in pairs.
On several occasions, residents have mistakenly assumed that Madam Liew, Ms Koh, or their teammates are sales people.
"They think you are selling things," Ms Koh said. "Or they think: 'Are you here to check up on me?'"
Not everyone is immediately friendly either, added Madam Liew. "In community work, there are bound to be people who will tell you off," she said.
In her experience, perseverance often pays off.
"Sometimes, if you continue to talk to them, they will thank you for stopping by. You've got to have the patience and the passion."