If you’re feeling ill, visit the nearest pharmacist (often distinguished by a green cross above the shop-front). Most will speak good English and will usually be able to offer a diagnosis and free advice and, if necessary, can also issue some prescription drugs. Often open from 08.00-21.00 or later, the pharmacy is a good first port of call if you are unwell.
Three years ago I was staying in Chiang Mai when I was bitten by a dog in the street. It was more of a nip than a bite, but it drew blood. Aware of the potential for rabies or other infection, I followed my own advice and visited the nearest pharmacy. The pharmacist was wonderful. He was still laughing and joking as he directed me to the nearby Suan Dok Hospital; “If you not die, you come back Chiang Mai!”
I was extremely impressed with the treatment at Suan Dok Hospital. The Suan Dok Hospital is not one of the main international hospitals in Chiang Mai, but the staff all spoke excellent English to make up for my faltering Thai. After having my details processed by computer, I went to a separate counter where I paid for and collected the vaccine. I was then led to another room where the anti-rabies injection was administered. The whole process took approximately 30 minutes and was very cheap (far less than the excess on my travel insurance). I had to go back a number of times over the following weeks to complete the course of jabs and was always impressed by the staff and the hospital itself. Of course, I don’t know if this is representative of all Thai hospitals, but if you are unfortunate enough to require medical attention you should be in safe hands.