I do not recommend calling 1669 -- you could end up anywhere, and in Thailand there is unfortunately a lot of corruption surrounding where ambulances/rescue vehicles take people.

Think through where you would want to be taken and get the ambulance number of that hospital. In the case of larger private hospitals it may be possible to go register your home address with them to ensure the ambulance finds you easily. While at it, register to get a patient number and either see a doctor or have a check-up sop that your basic medical history is on file already, this is very helpful should you be brought in unconscious or incoherent.

It is still best not to wait for an ambulance but rather take the first available transport to the ER if you can - ambulance only if not possible to safely move. (This is actually true in the West as well - remember that it doubles the time since the ambulance has to leave the hospital to reach you. You can already be there by the time it would have arrived at your home). Exceptions in case of possible spine injury as in an accident, w=in which case untrained people should not move the patient.

If away from home and upcountry, best option is to go to the ER of the nearest provincial or regional hospital for immediate stabilization and then request transfer to the hospital of your choosing from there.

By the way, IMO the very best ER care to be had in Thailand is in the major government teaching hospitals like Chula, Siriraj, KKU etc. The usual issues of a governement hospital (queues etc) do not apply in a true emergency, there will always be specialists on duty even in the middle of the night, and the ER staff have more experience than anyplace else.

Do what a friend of mine did and marry a nurse.

Do what a friend of mine did and marry a nurse.

Or a doctor, I've seen some hot women doctors.