Dr Joshua Lam volunteers twice a month at HealthServe which provides low-cost medical care for migrant workers.

Every Tuesday and Wednesday night, a long queue of migrant workers forms outside a small clinic in Geylang. They are here for the low-cost medical care.

Consultation is free for special pass holders while work permit holders pay $5. The clinic is run by non-profit organisation HealthServe, with the help of volunteer doctors, nurses and healthcare professionals.

A doctor at the Institute of Mental Health, Dr Joshua Lam currently volunteers twice a month at the clinic.

"I decided to volunteer for HealthServe because I wanted to play a part for migrant workers after seeing them at the polyclinics where I used to work. I know that they are always hesitant to seek treatment because of the cost, given that they are non-residents," said Dr Lam, who is single.

The 30-year-old started volunteering at HealthServe in July 2015 and sees around 15 to 20 patients a night.

HealthServe was founded in 2006 in order to provide affordable healthcare services to migrant workers.

In 2015, it provided medical consultation for 4,618 workers and helped nearly 500 on their workplace injury or salary/contractual issues.

The migrant workers come primarily from China, Bangladesh and India.

In this episode of video series Heroes Among Us, Dr Lam talks about his experiences helping the workers at the organisation.