TL;DR:Call 1669 for ambulance and medical emergencies in Thailand (1646 is an alternate public EMS number in parts of Bangkok); 191 = police, 1155 = tourist police.
For a medical emergency in Thailand, dial 1669 — this is the nationwide public ambulance and emergency medical hotline. 1669 connects you to ambulance dispatch and emergency-care coordination across provinces. In Bangkok you can also reach certain public EMS centres via 1646, but 1669 remains the universal number for ambulance response. Do not confuse this with other emergency lines: 191 is police, 1155 is tourist police. If you are in a private hospital network you know (for example BDMS hospitals), they may have direct emergency lines, but always call 1669 first for urgent ambulance dispatch. Sources: U.S. Embassy local resources and major Thai hospitals (Bumrungrad, Bangkok Hospital) confirm 1669 as the official medical/ambulance number.
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