Cold Immersion: The Ancient Practice Rebooting Modern Bodies
Cold immersion isn’t a fad. It’s a return to how humans used to live, feel, and adapt—before central heating and comfort smothered our biology.
This is one of those practices that’s been hard for me to adapt because I despise being cold. 😆
Aside from rinsing the conditioner out of my hair with cold(ish) water in the shower (because cold water closes the hair cuticles and makes it more shiny!) and maybe doing some cold face plunges (more on that below), I’ve only done one proper cold plunge in my life. And I didn’t like it, not one little bit. LOL
But it does have incredible benefits. Perhaps we can all talk ourselves into it together as we take a deep dive into all things cold plunging (see what I did there 😉).
By the breath of God ice is given, and the broad waters are frozen fast. Job 37:10
The Ancestral Blueprint
For most of human history, temperature wasn’t regulated. People got cold. They endured winter without modern insulation, sometimes on purpose, sometimes just by surviving.
Cultures turned this hardship into ritual:
Russia has the banya—sauna followed by plunging into frozen lakes or snow.
Finland and Scandinavia cycle between sauna and icy dips.
Japanese misogi includes waterfall meditations in winter cold.
These were more than traditions—they were resilience training.
Today, we live in a temperature-controlled cocoon. Always warm. Always stable. As cozy as that is, the constant comfort weakens us. Our ancestors had dynamic physiology—ours has gotten soft. Cold immersion is a way to restore resilience.
Why Cold Exposure Works: The Benefits
1. Hormetic Stressor = Stronger Body and Mind
Cold is a controlled stress. You stress the system—briefly—and it rebounds stronger. This kind of stress builds:
Resilience to physical and psychological challenges
Improved cardiovascular tone
Better emotional regulation
2. Fat Loss: Activates Brown Fat and “Beiges” White Fat
Brown fat burns calories to create heat. Cold immersion:
Stimulates brown fat activity
Converts white fat to metabolically active “beige” fat
Improves thermogenesis and metabolism
3. Mitochondrial Upgrade
Cold strengthens mitochondria—the engines of your cells:
Boosts mitochondrial density and efficiency
Enhances ATP production (cellular energy)
Slows cellular aging
Hormones and Nervous System: What Cold Does to Your Core Control Systems
Hormonal Surges That Change You
Norepinephrine rises up to 500%. This sharpens focus, boosts mood, and mobilizes fat.
Dopamine can spike up to 250%. Elevated for hours, it improves motivation, attention, and drive.
Cortisol rises briefly, then drops over time with regular practice—lowering baseline inflammation and stress.
Testosterone and LH may increase, especially in men, supporting energy and libido.
Insulin sensitivity improves, helping regulate blood sugar and burn fat.
Thyroid activity adapts by converting more T4 to T3 (the active form), fueling metabolism and heat production.
Nervous System: Stress Training + Recovery Rewiring
Sympathetic system (fight or flight) activates instantly, teaching your body how to handle and process stress.
Parasympathetic rebound kicks in after. The vagus nerve is stimulated, dropping heart rate and enhancing calm.
Over time, you gain autonomic flexibility—the ability to shift smoothly between alert and relaxed states. This is a big deal for nervous system health.
Face-First: Cold Water Plunges for Nervous System Recovery
Cold water on the face activates the dive reflex, a powerful parasympathetic response that slows heart rate and calms the nervous system. This is a gentle, effective way to begin cold exposure.
Cold Face Immersion Triggers the Mammalian Dive Reflex
Stimulates parasympathetic mode
Slows the heart rate via the vagus nerve
Calms the nervous system instantly
Improves HRV (heart rate variability) and stress recovery
Takes 30–60 seconds in a bowl of ice water to be effective
Perfect for:
Beginners easing into cold exposure
People with burnout, anxiety, or dysregulation
Nervous system tuning on high-stress days
How to Do Cold Immersion Safely and Effectively
Water Temperature:
Beginners: 50–59°F (10–15°C)
Advanced: 35–45°F (1–7°C)
Duration:
Start with 1–2 minutes
Work up to 3–5 minutes
Weekly total goal: 11 minutes
Frequency:
2–4 times per week is optimal for benefits without overtaxing the system.
Sauna + Cold: Which First?
Cold after sauna: Ends with a stressor, good for focus and adrenaline.
Sauna after cold: Promotes recovery and deep relaxation.
Wait 5–15 minutes between to let your system recalibrate.
Shivering Is Good
Let it happen. Shivering activates muscles and brown fat, driving thermogenesis. Don’t warm up too fast. Let your body build its own heat—this is where transformation happens.
Can Cold Immersion Be Harmful to Hormones?
Yes—if abused.
Chronic overexposure can suppress thyroid and disrupt reproductive hormones
Some women may notice menstrual changes if cold is overdone or mistimed
Overuse can elevate cortisol chronically, leading to burnout or fatigue
Balance matters. More is not better. Cold is a tool. Use it to support, not be a hero.
Best Time of Day?
Morning: Best for alertness, fat burning, and dopamine boost.
Afternoon: Helps reset if energy crashes.
Evening: Avoid if you’re sensitive—it may delay sleep due to norepinephrine/dopamine spikes.
Pro tip: Cold in the morning, heat in the evening mimics ancestral rhythms and supports circadian biology.
Who Should Not Do Cold Immersion?
Avoid or modify if you:
Have heart conditions or arrhythmias
Are pregnant
Have Raynaud’s or other circulation issues
Have epilepsy or seizure history
Are in an immunocompromised or extreme fatigue state
Cold immersion is the ancient technology of your body. It flips switches inside your body that modern life has left dormant: fat burning, stress adaptation, mental clarity, mitochondrial firepower. 💪🏻
It may take me a while to get there, but I know at some point, I’ll pull this tool from the toolbox when I most need it.
For the moment all discipline seems painful rather than pleasant, but later it yields the peaceful fruit of righteousness to those who have been trained by it. Hebrews 12:11