Bangkok, Thailand's capital, is a city of more than 10 million people, but it has few public ambulances.
In order to fill the gap, which stands at 1 ambulance for ever 67,000 citizens, a volunteer service began to run its own ambulances.
While it used to have an unsavoury reputation, however, things are now changing. The volunteer services have developed into highly organised teams who are proud of their self-appointed roles.
Al Jazeera's Aela Callan in Bangkok has more.