Pulse Plunge
A hand-crafted asnaro cold tub that turns deliberate cold exposure into a calm, measurable practice — with live water-temperature tracking, structured timing, and trend analysis through the Yutori app.
20% non-refundable deposit · 12-week lead time
The Tub
Asnaro: built to live outdoors.
A deep, single-person Japanese ofuro, hand-built in asnaro (Hiba) and designed specifically for outdoor cold-water use. Asnaro’s tight grain and natural resins make it more resistant to rot and checking than soft hinoki.
Outdoor-ready durability
Asnaro has higher natural resistance to decay, insects, and long-term water exposure than soft hinoki, making it better suited for frequent filling and draining outside.
Warm, understated look
Pale golden wood that harmonizes with your clear-cedar Pulse Sauna without trying to match every board.
Traditional construction
Thick asnaro staves, stainless/brass hardware where needed, smooth interior surfaces, and simple, rectilinear lines that feel timeless.
Design Philosophy
Why no chiller?
Pulse Plunge is intentionally passive: a hand-built asnaro tub plus a sensor and app, not a noisy machine.
Less complexity, more reliability
Chillers add pumps, fans, compressor noise, plumbing, and new failure points. A passive tub means quieter operation and fewer things to maintain or repair.
“Cold enough” for adaptation
Most people experience strong responses in the 45–60 °F range. With shade, overnight cooling, and occasional ice, this is achievable without mechanical chilling.
Traditional ofuro philosophy
Japanese ofuro are treated as a ritual rather than a precisely controlled system. We preserve that simplicity: a tub you fill, cool naturally, and step into.
Future flexibility
Your chiller options and your tub are decoupled. Add any third-party chiller later and use Pulse Plunge as the vessel; the sensor and app will still track actual water temperature.
Water Management
Practical water guidance.
Without integrated filtration or chilling, treat Pulse Plunge like a high-end soaking tub, not a permanent pool. Short, regular water changes are the safer default for a cold, outdoor tub.
Regular water changes
Daily use (1–2 people): change every 2–4 days. Heavy use: daily or every other day. Watch for cloudiness, odor, or surface film.
Pre-shower rule
Rinse off first to keep sweat, skin oils, and sunscreen out. Standard practice in Japan and makes a noticeable difference in water clarity.
Shade and cover
Use a fitted wooden or insulated cover when not in use. Reduces UV-driven algae growth, organic debris, and temperature swings.
Simple skimming
Use a small hand skimmer after sessions to remove leaves or insects. Rinse interior surfaces with fresh water before refilling.
The Yutori App
Sensor, coaching, and safety — built in.
Every Pulse Plunge ships with a Pulse Plunge Sensor and the Yutori mobile app. Submerged Bluetooth sensor reports water temperature in real time to your phone.
Live Water Temperature
Submerged sensor reports water temperature in real time. See exactly how cold the water is—not just “about mid-40s.” IP68/IP69K housing handles ice baths, splashes, and hose-downs.
Automatic Plunge Logging
Each plunge captured with duration, start/end temps, complete water-temperature curve, and peak heart rate and HRV change when paired with a compatible wearable.
Live Coach
Builds a personal cold-exposure window from your recent sessions, current water-temperature zone, and demographic factors. Simple states: “short primer dip,” “strong round,” or “time to get out.”
Long-term Analysis
Average plunge duration, typical temperature range, cold-shock peak heart rate, and how long you can stay at a given temperature while staying within guardrails.
Emergency Alert System
Monitors for signs of serious trouble during plunge sessions. If thresholds are met, the app triggers escalating alerts on your phone, notifies pre-selected emergency contacts, and where supported, initiates an emergency call workflow.
This system is a backup, not a guarantee. It depends on sensor data, device connectivity, and local emergency-call capabilities.
Site & Integration
What you need on-site.
Level, well-drained pad
Pavers or concrete sized to the tub with space to step in and out. Grade sloped so splash and rinse water moves away from the base.
Water source
Fill-and-refresh cold tub. Use ambient well/city water, ice, or pre-chilled water if you have a separate system—no integrated chiller required.
Wi-Fi or Bluetooth coverage
Reliable signal at the tub so Yutori can log data and, if needed, run emergency alerts.
Optional: Pulse Sauna pairing
Designed to sit beside Pulse Sauna for contrast sessions. Yutori treats alternating hot and cold as a single contrast session with adjusted timing.
Pricing & Delivery
$14,975, plus freight.
Hand-crafted asnaro cold tub with Pulse Plunge Sensor and lifetime Yutori Premium. Actual shipping quoted based on location and access.
Deposit
20% non-refundable deposit due at order signing to secure your build slot and materials.
Balance
Remaining 80% plus actual shipping cost due prior to shipment or at delivery, per your purchase agreement.
Lead time
Target delivery within 12 weeks of signed agreement, subject to asnaro availability and international freight timing.
Deposit is non-refundable and reserves your build slot. Full terms specified in the purchase agreement signed at contract.
Specifications
Full specs.
| Product name | Yutori Labs: Pulse Plunge |
| Tub type | Asnaro (Hiba) Japanese ofuro, hand-crafted for outdoor cold use |
| Exterior size | Approx. 56″ L × 30″ W × 26–28″ H |
| Interior depth | ~22–24″ water depth for seated full immersion |
| Material | Solid asnaro staves, traditional joinery, stainless/brass hardware |
| Finish | Smooth interior, natural asnaro surface |
| Use case | Outdoor cold plunge, no integrated chiller |
| Sensor | Pulse Plunge Sensor (RuuviTag Pro-class, temp + motion) |
| Sensor temp range | −40 to 85 °C (−40 to 185 °F) |
| Sensor protection | IP68/IP69K housing for submersion and spray |
| App | Yutori iOS app with Apple Health integration, HR/HRV, Live Coach |
| Included access | Lifetime Yutori Premium for this tub’s owner |
| Price | $14,975 USD plus freight · 12-week lead time · 20% non-refundable deposit |
Important
Safety & limitations.
Pulse Plunge and the Yutori app make cold exposure easier to structure and safer to explore, but there are important limits to keep in mind.
Not a medical device
Pulse Plunge, the plunge sensor, and the Yutori app are not medical devices and are not intended to diagnose, treat, cure, or prevent any disease. They should not replace medical advice, screening, or supervision from your healthcare team.
Hypothermia risk
Cold water immersion carries inherent risks including hypothermia, cold shock response, and cardiac stress. Start conservatively, follow the Live Coach’s recommendations, and never plunge alone without safety measures in place.
Connectivity-dependent emergency alerts
The emergency alert system depends on your phone, sensors, and network. If Wi-Fi or cellular service is poor, if your phone battery is dead, or if permissions are disabled, emergency workflows may be delayed or unavailable.
Heed your own limits
The Live Coach’s guidance is conservative by design, but it is still an estimate. If you feel unwell, confused, or distressed, end the session immediately and seek help—regardless of what the app is showing.
Your cold practice. Your data. Your ritual.
$14,975 plus freight. 20% deposit reserves your build slot. Target delivery within 12 weeks of signed agreement.