A cold-stimulus headache, colloquially known as an ice-cream headache or brain freeze, is a form of brief pain or headache, commonly associated with consumption (particularly quick consumption) of cold beverages or foods such as ice cream, popsicles, slushies, and snow cones. It is caused by a cold substance touching the roof of the mouth, and is believed to result from a nerve response causing rapid constriction and swelling of blood vessels, "referring" pain from the roof of the mouth to the head. The rate of intake for cold foods has been studied as a contributing factor. It can also occur during a sudden exposure of the unprotected head to low temperatures, such as by diving into cold water. A cold-stimulus headache is distinct from dentin hypersensitivity, a type of dental pain that can occur under similar circumstances.
Cats and other animals have been observed exhibiting a similar reaction when presented with a similar stimulus.
History
According to The New Yorker, the first written account of a cold-stimulus headache comes from Patrick Brydone in the 1770s. Brydone described a British naval officer in Sicily who consumed a large bite of ice cream and spat it out "with a horrid oath".
The term ice-cream headache has been in use since at least January 31, 1937, contained in a journal entry by Rebecca Timbres published in the 1939 book We Didn't Ask Utopia: A Quaker Family in Soviet Russia. The first published use of the term brain freeze, in the sense of a cold-stimulus headache, was in 1986.