The Protocol / Phase 2

2

Autonomic Reset

Cold exposure and heat cycling restore the nervous system's capacity to oscillate. Chronic stress creates stuck states. Temperature forces movement.

Duration 4 Weeks
Daily Time 10–20 minutes
Teachers Cold, Heat
Prerequisite Phase 1 Complete

Overview

Why Temperature Works

The autonomic nervous system was designed to oscillate. Sympathetic activation (stress response) should be followed by parasympathetic recovery (rest response). Modern life keeps most people locked in chronic sympathetic activation. The system forgets how to shift.

Cold exposure triggers the mammalian dive reflex: immediate parasympathetic activation that overrides stuck sympathetic states. It forces the system to shift whether it wants to or not. Heat does the opposite: it activates then deeply relaxes, training the oscillation in the other direction.

Together, they restore autonomic flexibility: the capacity to respond appropriately to demands and then recover. This is what healthy nervous systems do automatically. Traumatised systems must relearn it.

❄
Cold
→
⚡
Sympathetic Spike
→
🌊
Parasympathetic Flood
→
◎
Calm Baseline

Protocol 1

Cold Exposure

❄

Cold Shower Protocol

Progressive adaptation over four weeks

30s
Week 5
1min
Week 6
2min
Week 7
3min
Week 8
  • Week 5: End every shower with 30 seconds of cold. Start lukewarm, go colder over the week. Focus on maintaining nasal breathing (from Phase 1). The breath is the control.
  • Week 6: Extend to 1 minute. Begin with water on extremities (arms, legs), then torso, then face and head. Face triggers dive reflex most strongly.
  • Week 7: Extend to 2 minutes. Notice the "second wind" that comes after initial shock. This is the parasympathetic response kicking in.
  • Week 8: Extend to 3 minutes or begin the session with cold (rather than ending with it). The goal is comfortable discomfort, not suffering.
The breath is everything. If you're gasping or hyperventilating, the cold is too cold or too long. Slow nasal breathing during cold exposure is the skill. When you can breathe calmly in cold water, you can breathe calmly anywhere.
Caution: Do not do cold exposure if you have heart conditions, Raynaud's syndrome, or are pregnant. Start conservatively. The goal is adaptation, not endurance contest. If you feel faint, stop immediately.

Protocol 2

Heat Practice

♨

Heat Exposure

Sauna, hot bath, or hot shower

10-15
Minutes
2-3x
Per Week
Optional
Contrast Cycling
  • Access what you have: Sauna is ideal but not required. Hot bath works well. Even a hot shower at maximum tolerable temperature provides benefit.
  • Duration: 10-15 minutes of heat exposure. You should be sweating. The goal is to raise core temperature enough to trigger heat shock proteins.
  • Contrast cycling (optional): Alternate between heat and cold. 10 minutes hot, 1 minute cold, repeat 2-3 times. End on cold. This trains the oscillation more intensively.
  • Post-heat: Allow gradual cooldown. Don't immediately blast cold unless doing contrast. Notice the deep relaxation that follows heat.
Heat teaches surrender. Unlike cold (which demands you engage), heat asks you to yield, to let go, to soften. Notice what resists letting go. That resistance is information.

Integration

The Weekly Rhythm

  • Daily: Cold shower ending (as per weekly progression). This is non-negotiable.
  • 2-3x per week: Heat exposure (sauna, hot bath, or extended hot shower).
  • 1-2x per week: Contrast cycling if accessible (sauna to cold plunge, or hot bath to cold shower).
  • Continue Phase 1: Floor sleeping, nasal breathing, and tongue posture continue throughout. They are the foundation everything builds on.

The minimum effective dose is cold showers. If you have no access to sauna or bath, cold showers alone will provide significant benefit. Don't let perfect be the enemy of good.

Progress Markers

How You Know It's Working

Week 5

Cold feels shocking but tolerable. Breath control is difficult. Post-cold feeling of alertness and aliveness.

Week 6

Cold becomes less shocking. Breath control improving. May notice improved mood, particularly in mornings after cold.

Week 7

Beginning to "look forward to" cold (or at least not dread it). Parasympathetic response more accessible. Sleep may improve.

Week 8

Cold feels almost meditative. Heat-cold contrast produces profound relaxation. Baseline anxiety often noticeably reduced. Recovery from stress faster.

The Science

What's Happening Physiologically

Cold exposure triggers norepinephrine release (2-3x baseline), which improves focus and mood. It activates brown fat thermogenesis, improving metabolic function. Most importantly, it forces vagal activation through the dive reflex, training the parasympathetic system to come online.

Heat exposure triggers heat shock proteins, which repair cellular damage and reduce inflammation. It increases growth hormone, supports cardiovascular function, and trains the body's cooling mechanisms. The deep relaxation following heat is parasympathetic activation.

Together, they restore what chronic stress destroys: the ability to move fluidly between activation and recovery. See the Evidence section for research citations.

Completion Criteria

Before Moving to Phase 3

  • I complete at least 2 minutes of cold shower daily with controlled nasal breathing
  • I have integrated heat exposure 2-3x per week (or daily cold if no heat access)
  • I notice improved baseline mood and/or reduced anxiety
  • I can enter cold without gasping or panic within the first 10 seconds
  • Phase 1 practices (floor, breath, tongue) remain consistent
  • I have completed a minimum of 4 weeks of Phase 2