Final answer:
The universal choking sign is when a person holds both hands on their neck, indicating that they are unable to breathe due to an airway obstruction. Immediate action such as back slaps or the Heimlich maneuver is necessary, and emergency services should be called if the obstruction doesn't clear.
Step-by-step explanation:
If an adult or child is choking, the universal sign that they may use to indicate they need help is when a person holds both hands on their neck. This gesture is a call for assistance, and it is recognized worldwide. A choking person cannot speak or cry out, and if possible, breathing is labored, producing gasping or wheezing. They might also clutch at their throat or mouth in a desperate attempt to clear the obstruction.
When encountering someone who is choking, it is critical to take rapid action. If it's an infant, one might turn the baby upside down and gently slap their back. For older children and adults, encourage them to cough, deliver several firm back slaps, and if needed, perform the Heimlich maneuver. Remember, if the obstruction doesn't clear, immediately call for emergency medical help.
It's important to note that foods like bananas and marshmallows, which can mold to the shape of the pharynx, are particularly dangerous and pose a choking risk. In the event of choking, timely and appropriate response can save a life.