This nerve makes it possible for you to feel sensations in your face, including pain. Scientists believe the blood vessels in the throat and mouth and the trigeminal nerve are central to what makes a brain freeze hurt. But they don’t quite agree on which is more responsible for causing the pain. Most agree that eating or drinking something cold, too quickly, rapidly lowers the temperature at the back of your throat and roof of your mouth. Many also agree this causes the tiny blood vessels in these areas to shrink, allowing less blood to pass through them. This reduces their ability to supply your brain with necessary oxygen in the blood. What happens next is a little blurry.
