TGIF, thinks Dai. After a full day working for an international bank, the petite and soft-spoken thirty-two-year-old races to the Lumpini Park gates where friends whisk her away for a night on the town. She will limp home at 5:00 AM, having seen four gruesome car wrecks and one suicide.

Dai is a volunteer for the Por Tek Tung Foundation, Thailand’s largest provider of emergency medical services (EMS). Created by Chinese immigrants in the capital of Bangkok more than one hundred years ago, Por Tek Tung began by offering free funeral services for the city’s poor, and now specializes in quick-response rescues. You can spot its staff—over a thousand, nearly all unpaid—by their distinctive blue jumpsuits as they drive around in packs, on the lookout for road accidents.

If this sounds a touch morbid, consider that, last year alone, a motorist was killed in Bangkok ...