Chapter 15: The Thermoneutral Trap
You live in a 3-5 degree temperature bubble year-round. Your ancestors experienced 15-30 degree daily swings. Eliminating thermal stress is eliminating a signal your body needs to stay healthy.
◆ Key Insights
Brown fat -- metabolically active tissue that burns calories to generate heat -- atrophies when you never get cold
Finnish sauna studies show a 40% reduction in all-cause mortality for frequent sauna users over 20 years
Cold exposure activates norepinephrine, reduces inflammation, and improves insulin sensitivity through hormesis
Sleeping in a room at 19C (66F) instead of 24C increases brown fat activation and improves metabolic markers
The dose makes the medicine: small, controlled thermal stressors trigger adaptation. Eliminating them triggers decay
Read the full chapter to discover why comfort is slowly killing your metabolism -- and how deliberate discomfort reverses the damage.
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