Elmer Chan, 21, has never stepped into a foreign worker dormitory. Nor does he have any healthcare or medical expertise to offer.

But it did not stop him from volunteering to be a "swabber", taking biological samples from migrant workers in dormitories and those in quarantine in hotels to be tested in a laboratory for the coronavirus.

The task is physically draining, even for the young adult. Standing for hours under the sun in a carpark or dorm yard to do the tests, he is often drenched in sweat with the heat trapped beneath the full protective gear. He takes about 60 swab samples each day, five or six days a week.

"Of course, I get anxious sometimes about the risk of infection. What if there is a tiny gap in my gear and I get infected and spread it to others? That is why I have to keep the infection control measures in mind," said Mr Chan, who graduated from Temasek Polytechnic last month with a diploma in aviation management and services.

After a seven-hour shift, he goes home and sprays down his trousers and shoes with disinfectant at his front door before he goes inside.

He is usually so exhausted that he naps for a few hours, then checks his text messages to find out where he has to be for the next few days.

Mr Chan is one of some 7,200 non-medical volunteers from various backgrounds, ranging from Grab drivers to teachers to housewives, who have joined the SG Healthcare Corps in the fight against the coronavirus. They may assist on the front line, helping to take swabs or blood for tests. Others may support the care of seniors, by being a community care ambassador or a healthcare assistant.

In addition to the SG Healthcare Corps, individuals have also been finding other ways to volunteer on the front line, by signing up directly with non-profit organisations or dormitories.

The Ministry of Health (MOH) said in response to queries that as of May 11, it has received responses from more than 12,900 people keen to join the SG Healthcare Corps.

Among these people, 5,700 of them are healthcare professionals such as dentists, pharmacists and medics.

About 2,500 people have been matched with healthcare institutions and are undergoing training or being deployed to those institutions.

MOH said the institutions assess where volunteers are most suitable. Training is also provided.

The SG Healthcare Corps was launched on April 7 to support the healthcare workforce in the fight against Covid-19. It was first open to former and current healthcare professionals. Later, the call was extended to non-healthcare professionals. The positions are paid.

The MOH spokesman said safety of the volunteers is of "utmost priority", requiring precautionary measures and training, such as how to use personal protective equipment.

Dr Lim Lii, president of the Singapore Dental Association, is volunteering to carry out swab tests in the community and training would-be swabbers.

Potential swabbers, as the Health Promotion Board calls them, first go through an e-learning module on infection control and swab techniques.

The practical component is learnt in the classroom as well as on the job, observing and assisting experienced swabbers.

Dr Lim said she has trained volunteers between the ages of 18 and 60 from all walks of life, such as students, medical professionals, flight attendants and salesmen.

"On average, a swabber can do 20 to 25 swabs per hour but experienced ones can go up to 35 an hour," said Dr Lim.

"Conditions on the ground can be quite challenging as some are not used to being all covered up in protective gear and they may get heatstroke or not feel well."

Yet for many, having a direct impact makes the work rewarding.

Said Mr Chan: "I was sent a video of the foreign workers in the dorm clapping for us from their rooms and corridors after we were done with the shift and it is such moments of appreciation that I treasure."

Though MOH declined to reveal the volunteers' remuneration, the Health Promotion Board has advertised for swab assistants at $3,400 a month and swabbers at $3,800.

HealthServe, a non-government organisation which serves the needs of migrant workers, says it has also seen a rise in the number of volunteers for certain programmes.

Ms Suwen Low, head of communications and engagement at HealthServe, said it now has some 100 people supporting its virtual counselling clinic. In the past, there would be 10 volunteers for in-clinic counselling services in Geylang and Little India.

Educator Saad Hashmi, 28, responded to a call for volunteers at the S11 Dormitory @ Punggol in April.

Helping to manage thousands of foreign workers and handle meal distribution while wearing full protective gear took some getting used to and some volunteers dropped out after the first day. Mr Hashmi lives onsite in the Punggol dorm with a few other volunteers and eats the same meals catered for dorm residents.

A few weeks ago, the S11 dorm management converted the group of volunteers to contract staff, and will be paying them $15 to $18 an hour. Said Mr Hashmi: "They didn't want us to do it for free, especially since many of us were not earning money elsewhere."

Another volunteer, Mr Maran Paramanathan, 52, deputy director of air navigation services (policy) at the Civil Aviation Authority of Singapore, has helped out since April 20 in two dormitories in Changi East housing 1,500 migrant workers building Changi Airport's Terminal 5.

His previous experience as a commander in the air force has enabled him to put better systems in place such as creating smoking corners and hot water points on every floor, to minimise workers having to move about, as well as speeding up food distribution by pre-sorting the food by floor.

"My family thought they could see more of me during this work-from-home period," said Mr Paramanathan with a laugh.

"Their biggest worry is that I am exposing myself to the risk of getting infected but it is a necessary sacrifice. I am prepared to take the risk."