What This Protocol Covers
This is your entry point into deliberate thermal exposure. Not a casual “sit in the sauna until you feel like leaving” approach - this is a structured, progressive 30-day protocol designed to build your heat tolerance safely, establish a tracking baseline, and set up the habits that make long-term thermal practice sustainable.
By the end of four weeks, you will have a measurable baseline for your heat response, a consistent routine, and the confidence to progress into intermediate protocols.
Who This Is For
You have access to a sauna - traditional Finnish, infrared, or a quality portable unit - and you want to use it with intention. Maybe you have read about the cardiovascular and longevity research coming out of the University of Eastern Finland. Maybe you just want to recover better. Either way, you have never followed a structured heat exposure protocol before, and you want to do this right.
If you have any cardiovascular conditions, are pregnant, or take medications that affect blood pressure or thermoregulation, consult your physician before starting. This is non-negotiable.
Prerequisites
- Access to a sauna (any type) with reliable temperature control
- A way to track time (phone timer works fine)
- A water bottle you will actually bring inside with you
- Optional but recommended: a wearable that tracks heart rate and HRV (see our HRV setup guide)
The 4-Week Progression
Week 1: Acclimation
Goal: Get your body used to the environment. Do not chase intensity.
- Sessions: 3 times, with at least one rest day between sessions
- Temperature: 70-75°C (158-167°F) for traditional sauna; 50-55°C (122-131°F) for infrared
- Duration: 10-12 minutes per session, single round
- Cooldown: Step out, sit at room temperature for 5 minutes. No cold plunge yet.
Pay attention to how you feel at minute 8. That is your signal point. If you feel lightheaded, dizzy, or nauseous at any point, exit immediately.
Week 2: Building Duration
Goal: Extend your time under heat while maintaining comfort.
- Sessions: 3-4 times
- Temperature: Same as Week 1
- Duration: 14-16 minutes per session, single round
- Cooldown: Room temperature for 5 minutes, followed by a lukewarm (not cold) shower
You should notice that the first five minutes feel noticeably easier than Week 1. That is acclimation working. Your body is getting better at shunting blood to the skin for cooling.
Week 3: Introducing Rounds
Goal: Add a second round. This is where the real adaptation begins.
- Sessions: 3-4 times
- Temperature: 75-80°C (167-176°F) traditional; 55-58°C (131-136°F) infrared
- Duration: Round 1: 12-14 minutes. Cool down 5-8 minutes. Round 2: 8-10 minutes.
- Cooldown: Between rounds, sit or stand at room temperature. After the final round, cool shower (not ice cold).
The second round will feel harder than the first. Your core temperature is already elevated. This is the point - you are training your thermoregulatory system to handle sustained heat load.
Week 4: Establishing Your Routine
Goal: Find the session structure you can sustain long-term.
- Sessions: 4 times
- Temperature: 78-82°C (172-180°F) traditional; 55-60°C (131-140°F) infrared
- Duration: Round 1: 15 minutes. Cool down 5-8 minutes. Round 2: 10-12 minutes.
- Cooldown: Cool shower. If you feel ready, try 30 seconds of cold water at the end - but this is optional.
By Week 4, you should have a clear sense of your preferred session timing, how your body responds to the second round, and what your post-sauna recovery looks like.
What to Track
At minimum, record these after every session:
- Date, time of day, and sauna type
- Temperature and duration for each round
- Subjective heat tolerance (1-5 scale: 1 = easy, 5 = had to exit early)
- Sleep quality the night after (if you sauna in the evening)
- Resting heart rate and HRV the following morning (if you have a wearable)
After 30 days, you will have enough data to see patterns. Most people find that their heat tolerance score drops (improves) by 1-2 points over the four weeks, and that their HRV shows a measurable positive trend on rest days.
When to Stop
Exit the sauna immediately if you experience any of the following:
- Dizziness or lightheadedness that does not resolve within 30 seconds of sitting down
- Nausea or a feeling of “something is wrong” - trust your gut on this one
- Heart pounding uncomfortably (elevated heart rate is expected; discomfort is not)
- Tingling in your extremities or visual disturbances
- Headache that develops during the session
None of these are signs of weakness. They are your body telling you that you have exceeded your current capacity. Step out, hydrate, cool down, and try a shorter or cooler session next time.
If symptoms persist after exiting, seek medical attention. Thermal exposure is remarkably safe when done progressively, but it demands respect.
What Comes Next
Once you have completed this 30-day protocol, you are ready for intermediate programming - longer sessions, higher temperatures, structured cold contrast, and targeted protocols for specific outcomes like sleep optimization or athletic recovery. But those all build on the foundation you establish here.
Start conservative. Track everything. Progress will come faster than you expect.