Norwegian Researchers Used 84 Pig Tongues to Study What Happens When You Lick a Frozen Lamppost

Anders Hagen Jarmund got his tongue stuck to a frozen lamppost as a boy in Hattfjelldal, Norway. So did his friends. Years later, Jarmund -- by then a medical student at the Norwegian University of Science and Technology -- did what any self-respecting scientist would do: he decided to study it.

The result is two peer-reviewed papers, 84 pig tongues, one infrared camera, and a formal scientific name for the experience: tundra tongue.

856 cases from Scandinavian newspapers

The team's first study was a scoping review of Scandinavian media coverage dating back to 1748. They combed through more than 17,000 search hits and identified 856 reports of people freezing their tongues to cold metal, with the earliest case appearing in 1845. After accounting for stories covered by multiple outlets, they isolated 113 individual cases.

The demographics were exactly what you might predict. The peak age for getting your tongue stuck to frozen metal is five. Sixty percent of the cases involved boys.

Most cases resulted in no lasting harm. But 18% required medical attention, including cases of avulsion -- the clinical term for having a piece of your tongue torn off, typically from panicking and pulling too hard.

The study was published in the International Journal of Pediatric Otorhinolaryngology.

Enter the pig tongues

Having established that tundra tongue was both common and occasionally serious, the team wanted to measure exactly what happens when tissue meets frozen metal. They needed tongues -- lots of them -- but getting ethical approval for human volunteers was, in Jarmund's words, doubtful. After debating which animal tongue most closely resembles a human one, they settled on pig tongues. A licensed slaughterhouse north of Trondheim supplied 84 of them.

The experimental setup required considerable tinkering. The team rigged force sensors, an infrared camera, and multiple measurement devices, all of which needed to be synchronized. They warmed the tongues, cooled sections of a metal lamppost, and systematically applied tongue to metal at various temperatures. They also donated their own saliva to lubricate the tongues, since pig tongues from a slaughterhouse are not naturally wet.

The results: temperature matters more than you think

In 54% of experiments, pieces of the tongue were torn when pulled free. The harder the pull, the greater the likelihood of tissue damage. But the most interesting finding was about temperature.

The greatest risk of avulsion occurred in a specific range: between minus 5 and minus 15 degrees Celsius. At colder temperatures, the risk actually decreased. The team's hypothesis: at very cold temperatures, the tongue freezes hard enough that the tissue resists tearing when yanked free, whereas in the moderate-cold range, the surface layer bonds to the metal while the underlying tissue remains soft enough to rip.

The study was published in Head & Face Medicine.

What to do if it happens

The science-backed advice is simple. First, do not panic. Second, do not pull. Instead, warm the metal at the contact point -- breathing on it or applying a little warm water can loosen the bond. Norway was concerned enough about the problem to pass regulations in 1998 prohibiting bare metal in playground equipment.

The researchers behind the research

The project was a collaboration among friends who were also researchers: Jarmund, his brother Stale, Sofie Eline Tollefsen, and Cristoffer Sakshaug, with support from an associate professor in mechanical engineering and professors in pathology and biophysics. Stale used the pig tongue experiments as his master's thesis project.

Jarmund, who recently completed his medical degree and is finishing a PhD dissertation on preeclampsia, conducted much of the analytical work while on a research exchange in California -- far from any frozen lampposts.

The team had previously published a peer-reviewed assessment of healthcare-related social media memes. Tundra tongue, apparently, was the logical next step.