The human tongue is a complex neurologic organ. It’s actually supplied by numerous cranial nerves…5th cranial nerve providing general touch sensation, 7th cranial nerve involved in taste sensation to the anterior 2/3rds of the tongue, 9th and 10th cranial nerves sensing touch and taste to the posterior 1/3rd, and 12th cranial nerve providing motor function. At least five specialized taste receptors exist analyzing sweet, salty, sour, savory/ umami, and bitter proteins. As opposed to prior beliefs, there are no special regions of the tongue that are tuned to a particular taste… all types are registered in pretty much all areas. Taste proteins are sensed through these cranial nerves, to the thalamus, and then to the insula of the brain where they’re processed.
It turns out that heat is more socialist than Bernie Sanders or the Squad… heat will move from one place to another until everywhere is the same temperature (It’s a bit more complex than that since otherwise the whole world would be the same uniform climate). The resting temperature of the mouth is relatively high. This means that drinking or eating most anything will cool the mouth’s tissues, which is why most flavored liquids/ foods are served above oral conditions. And it’s the change in temperature that partly contributes to the magnitude of taste. We acquire less taste from refrigerated foods below oral temperatures. Furthermore, lower temperatures may reduce the excitability of certain taste perception.
As the tongue touches a frozen flagpole, its moisture is quickly robbed of heat because metal is a superconductor compared to our tongue. Now if our tongue were the uber functioning neurologic organ we expect from its abundant cranial nerve supply, our brain should alert us to remove our tongue quickly since we’re tasting icky frozen metal. However there’s a problem with the taste of metal, and especially cold metal. Metal is pretty complex, emitting ~ 3 different types of taste proteins, but is predominately sweet. Unfortunately for the average human, sweetness sensation is reduced at temperatures below about 200 Celsius, and freezing temperature is 00 Celsius.
Therefore upon our tongue touching the frozen pole… assuming you’re just tasting it because you didn’t see the movie or know what’s about to happen… the sweetness of the metal essentially cannot be processed. As our brain’s hamster is rapidly spinning the wheel of taste processing, the metal conducts the heat away faster than the tongue can replenish. Blood rapidly tries to bring heat back, but is too slow. The moisture in the tongue is robbed of heat, leading to our saliva freezing in the surface pores. Result??? The fire department is called to help remove Flick’s frozen tongue. The solution is using warm water to thaw the superficial layer so a portion of our gustation organ is not permanently left in the school yard.
Of course, the behind-the-scenes to “A Christmas Story” cheated the neuroscience and physics lesson, using a plastic suction tube to give the impression of attachment.