True choking is rare, says Art Hsieh, chief operating officer for the San Francisco Paramedic Association. When a person is really choking, he can’t cough strongly, speak, or breathe, and his face may turn red or blue.

What to Do Immediately: Call 911. For a victim age one or older: Have the person lean forward and, using the palm of your hand, strike his back between the shoulder blades five times. If that doesn’t work, stand behind the victim, place one fist above the belly button, cup the fist with your other hand, and push in and up toward the ribs five times, as in the Heimlich. If you’re alone: Press your abdomen against something firm, like a kitchen counter, or use your hands.

What Not to Do: Give water or anything else to someone who is coughing.

When to Seek Medical Attention: For a case of true choking, always call 911.