What can you do for someone who is choking on a glass of water?

Let them cough: When someone chokes on liquids it usually means they have gotten the liquid into their windpipe and the irritation causes them to cough. It is a reflex to try and get the material out of the trachea and into the esophagus where it should be. Patting on the back or repositioning the head are of no help. Simply let them cough and keep them upright as this will permit the most effective cough.

Choking: Speech and swallow specialist evaluation is indicated.

Get their head down: Get them in a position where their trunk and head are lower than their hips and allow gravity to assist in clearing the water from their lungs.