Every morning, hundreds of Burmese migrants turn up at Dr Cynthia's clinic in Mae Sot - some from nearby, others having travelled for days from deep inside Burma.
The patients come from all walks of life. Local people donated money so this monk could travel over the border, while the baby was born at the clinic to illegal migrant parents.
Saw Raymond's two sons carried him all the way from the Burmese city of Mandalay, because they felt there was no other way to cure his stomach complaint.
Maw Keh leads a team making prosthetics for landmine victims living in the border region. Many of the workers also have artificial legs, and know what a difference it makes.
Maw Keh estimates that only 30% of landmine victims survive. About a third die immediately of their injuries, while another third are not able to reach help in time.
The clinic has a special ante-natal unit. Dr Cynthia estimates that 80% of Burmese women give birth without a trained supervisor, and she sees this as a main priority for the clinic.
The clinic also offers drugs and advice for HIV patients. HIV/Aids is a growing problem in Burma: an estimated 600,000 Burmese are living with the disease.
The backpack medics have more rudimentary facilities, often working in people's homes, using make-shift equipment.
They spend much of their time trekking through dense jungle, trying to avoid landmines and Burmese soldiers.
The services they provide may be basic, but they are also life-saving.