In a big room at the Health Ministry, a din of English, Malay, Tamil and several Chinese dialects rings out as more than 100 people clustered at tables with laptops work the phones to track anyone who may have been exposed to severe acute respiratory syndrome (SARS).
The small conference hall has been turned into multiethnic Singapore's headquarters for tracking severe acute respiratory syndrome.
Soldiers and civil servants have been pressed into service, making between 1,000 and 2,000 calls per day to contact anyone who may have had a brush with SARS.
One feverish person on a flight, in an emergency room, or arriving at the border by land could result in 50 phone calls for the tracing unit -- before that person is even diagnosed with SARS. For example, people on the same flight as a suspected SARS sufferer must be contacted.
Captain Thomas Neo, who heads the team, gives his staff an informal one-day deadline to reach any new person on the list.
"We have 24 hours," Neo said. "That's how much time we have."
The team then gives out advice and refers suspected SARS cases to other agencies.
Staffers are trained to tell the person on the other end of the line to remain calm. They ask them to stay home and monitor their temperature until officials determine whether they need to stay in home quarantine, based on how close their contact was with an infected person.
Annie Chow, on loan from Singapore's National Environmental Agency, had a list of at least 20 numbers to call one morning this week.
"Don't panic, nothing to worry about. Just try to stay home and check yourself," she told one of them.
The 240 team members work shifts from 7am to 11pm tracing people from lists supplied by the Health Ministry, hospitals, border checkpoints and airlines.
More than half of the 204 people sickened by SARS in Singapore can be traced back to one woman who contracted the illness in Hong Kong in February. Her case made officials all too aware that just one person can spark a deadly new cluster.
A recent outbreak at Singapore's largest wholesale market, Pasir Panjang, gave the team a surge of new work. Eventually, 2000 people were tracked down and ordered to stay home.
"It was really bad when Pasir Panjang happened. We had to make so many calls in every dialect you can think of," said another volunteer who declined to be identified.
Singapore has some of the world's toughest anti-SARS measures, including fines and prison terms for quarantine breakers and health scans at all border checkpoints.
About 950 people are currently quarantined in Singapore -- many of them monitored by electronic camera to make sure they stay home.
Under recently amended laws, quarantine breakers face fines of up to 10,000 Singapore dollars (US$5,610) and jail of up to six months.
Singapore was the first country to start thermal imaging at its airport, where over 60,000 people have now been screened for fever.
Confirmed cases of SARS in the city-state have dwindled, with only 5 new cases in the past week.
Nonetheless, suspected cases continue to stream into the tracing unit, Neo said.
Singapore has recorded 27 deaths since the outbreak was reported just over 2 months ago. Globally, the disease has killed more than 475, and sickened more than 6,700.