World Changes Due to the Telephone. Within 50 years of its invention, the telephone had become an indispensable tool in the United States. In the late 19th century, people raved about the telephone's positive aspects and ranted about what they anticipated would be negatives.
When you hold the ice cube for a very long time, the enzymes deactivate. Blood circulation stops. The brain initiates impulses for blood circulation. The local nerves therefore get irritated and produce a sensation of heat.
International Headache Society gives detailed classification of brain freeze. Pain is caused by opening and closing of blood vessels that flow past the throat to the brain, normally when cold food or liquid is consumed quickly. Official name for 'ice-cream headache' is sphenopalatine ganglioneuralgia.