Have you heard of The Iceman? No, not the 5,300-year-old, fantastically preserved corpse, Otzi: We mean Wim Hof, a Dutchman famous for spending prolonged periods of time in, as his moniker suggests, extremely frigid environments.
Hof, who’s in his late 50s, has engaged in all kinds of chilly shenanigans. He’s run almost naked on marathons north of the Arctic Circle, scaled mountains in his underwear, and so forth. His seemingly superhuman powers have been the subject of several scientific papers – and a new study published in the journal NeuroImage suggests it may have something to do with his brain.
His personal website links his abilities to a technique of unusual breathing he himself developed. Understandably, researchers have been keen to find out what’s really going on here, physiologically speaking, but until now, much of the fascination has focused on his inhaling and exhaling.
This new study, led by a team at Wayne State University in Detroit, wanted to know what role his brain played too.
The authors stress that the ability of the body to withstand “environmental thermal challenges” is governed by the automatic nervous system (ANS). As the name suggests, this regulates plenty of bodily characteristics without any conscious input from the person themselves.
The question, then, is how is Hof seemingly “hacking” part of his own ANS? In order to find out, the team wired Hof up to several types of monitoring equipment, including magnetic resonance imaging (fMRI) to peer into his brain, and positron-emission tomography (PET), which tracks metabolic processes in the body.
Hof was also wearing a full-body suit which the team could inject with water at set temperatures at will. Throughout, as he engaged in his breathing technique, he was compared to a range of healthy participants in a control group.
Remarkably, it seems that Hof can willfully regulate his skin temperature and, potentially, his core body temperature, when exposed to the cold.
The team found that Hof’s unusual breathing leads to an increase in nervous system activity and an uptick in the consumption of glucose in his intercostal muscles, which help form the chest wall. This generates heat that makes its way to the lung tissue, ultimately warming circulating blood there.
“This may counteract a decrease in core body temperature that otherwise would have occurred from cold exposure,” the study surmises.
The brain plays a key role too. Their data suggests that such forced breathing, as well as the state of mind The Iceman enters, seems to active primary control centers involved in modulating sensory pain. Found in the upper brain stem, it’s thought that this control occurs through the release of pain-smothering opioids and cannabinoids.
This study doesn’t stand in isolation. Several others have been conducted, including one in 2014 which, using a group of volunteers mimicking Hof’s breathing, suggested that this technique triggers a flood of adrenaline. This was linked to increased levels of an anti-inflammatory protein that suppressed short-term, painful inflammation and related adverse effects.
Although it seems like Hof can manipulate his immune system in novel ways, the Iceman himself is known for his hyperbole. Sometimes, as stressed by an excellent rundown of Hof on Discover, he sometimes “begins to step beyond the edges of modern science” by making over-exaggerated and unfounded claims.
The bottom line is that, at present, we need far more peer-reviewed research to be conducted on Hof before we can say with any confidence what’s giving The Iceman his icy resilience.