Health services are public services that provide medical care
First off you should take them to the nearest hospital. If they are still talking and breathing well this means that the food or whatever is lodged in their esophagus. From what I've learned do not do the hiemlich maneuver because that can make it worse. This actually happened to my brother last week and he is now fine. I hope this helped you!
Always say no never consume anything that you are not sure of what the substance is and in this situation just don't go you can never be to safe at least that's what I would do anyway