I have had a very cold sensation in the middle of my chest for 4 days. it feels like there is a mass of bitter cold air in my chest. what might it be?

Interesting.: This can occur after drinking a very cold beverage. Normally it should get better in a few hours. Not common to last 4 days. I would advise you to see your family physician and let him/her examine you and listen to your lungs and palpate your abdomen which may be a long shot causing this complaint. Maybe a chest xray would be in order.