Sauna bathers understand the nonlinearity of a good sauna cool down. As the wind blows and steam billows, we have a grasp of how our bodies retain heat, even in sub freezing temperatures. Further, we understand that after a certain threshold of time, are bodies are fully cooled. We feel it, and at this point, we either towel off and get dressed, or head back into the sauna for another round.
An expression of this understanding can be represented as:

The vertical access (n) is heat. The horizontal access (f) is time. As we exit the hot room, and after we jump in a cold lake or dump cold water over our heads, are bodies are still plenty warm. And we remain so, nonlinearly. Even after a few minutes outside, our bodies still give off heat and we are relatively comfortable outside in the cold.
Yet after a certain time, our body heat starts to drop faster, and at a certain point we should be reaching for either our clothes to get dressed or, if we are between rounds, the hot room door to warm up for another round.
This concave nonlinearity is an example of “antifragile”* We have strength of body and mind. We gain from the disorder of temperature extremes. We are an example of how “some things benefit from shocks; they thrive and grow when exposed to volatility, randomness, disorder, and stressors and love adventure, risk, and uncertainty.”*
Inexperienced sauna bathers are fragile. When exiting the hot room, and leery of an ice cold lake plunge or dumping cold water over their heads, they are immediately more vulnerable to a cool breeze and cold temperatures. In other words, they feel as if they are getting cold quickly. They shiver and squirm. They reach the threshold to seek warmth much more quickly, even nonlinearly as a subject of time outside.



As people become more exposed to the authentic sauna experience, they garner the opportunity to develop “robustness” in their mind and body. By “listening to our core, not our skin” we start to extend our cool downs.
And we become “antifragile” because of it (a very good thing). We “strive and grow” from these “stressors.”
- better health – fewer to zero colds, flu, etc.
- better disposition – less prone to want to throw a plate against a wall in anger.
- more stamina – able to shovel the driveway in Troxers or minimal clothing. “Cold? eh… not so bad.”
For now, we know this intuitively and experientially, yet we welcome (and are seeking) clinical studies with more multisyllabic words to help explain why.
*Nassim Nicholas Taleb, author of Antifragile, The Black Swan, and other seminal books.