Terms of Use & Safety Guidelines

1. Provider and Scope

The provider of Cold Mastery is Fabian Weiß, Kolonnenstr. 8, 10827 Berlin, Germany (see legal notice).

These Terms of Use govern the use of the Cold Mastery app for Apple Watch and iPhone. You will be asked to read and actively confirm these terms when you first launch the app. The app cannot be used without this confirmation.

Cold Mastery is directed at consumers within the meaning of § 13 BGB (German Civil Code). Statutory consumer protection provisions apply.

Contractual Partner: For the use of Cold Mastery, your contractual partner is the Provider (Fabian Weiß). These Terms of Use govern the relationship between you and the Provider. The purchase and payment processing of in-app purchases and subscriptions are subject to the terms and conditions of the respective app store operator (Apple). The Provider has no influence over the purchase process and no access to your payment data.

Definitions:“App” refers to the software Cold Mastery in its current version for Apple Watch and iPhone. “User” or “you” refers to the natural person using the App. “Provider” or “we” refers to Fabian Weiß as operator. “Content” refers to texts, images, and information within the App.

2. Description of Services

Cold Mastery is a timer and tracker for cold exposure (cold showers, ice baths, open water cold exposure). The App includes in particular:

Countdown timer with configurable duration
Optional breathing exercise before cold exposure
Heart rate recording during sessions (via Apple HealthKit)
Progress tracking and streak display
Structured training programs with progression
Knowledge library with background information

Cold Mastery is expressly not a medical device and not a medical aid. The App does not replace medical advice, diagnosis, or treatment. The displayed heart rate values originate from the Apple Watch's optical sensor and are estimates, not clinical measurements.

The scientific information presented in the App and on the website serves general educational purposes. It does not constitute health or healing claims. The Provider does not guarantee any specific training or health outcome — in particular, no improvement in cold tolerance, stress resilience, or heart rate values. Individual results depend on personal factors beyond the Provider's control.

3. Health Information and Personal Responsibility

Cold exposure is a physical challenge that requires preparation and mindfulness. The following information summarizes the key risks. More detailed, context-specific safety information (e.g., specific to ice baths or open water cold exposure) is displayed directly in the App before you start a session.

3.1 Risks of Cold Exposure

Cold exposure can involve, among others, the following risks:

Cold Shock (Cold Shock Response) — involuntary gasping, hyperventilation, panic
Hypothermia — from excessively long or intense exposure
Cardiovascular stress — sudden increase in heart rate and blood pressure
Loss of consciousness — especially in connection with breathing exercises in or near water (Shallow Water Blackout)
Drowning — as a consequence of loss of consciousness or cold shock in water

The App supports you with timers, programs, and safety information — however, the decision of whether and how you practice cold exposure is yours. The Provider has no influence over the circumstances under which you practice cold exposure.

3.2 Contraindications

The Provider expressly advises against cold exposure in the presence of the following pre-existing conditions or states. In these cases, you should only use the App for active cold exposure after consulting your physician:

Cardiovascular diseases (including hypertension, cardiac arrhythmias, coronary artery disease)
Raynaud's syndrome
Epilepsy or seizure disorders
Pregnancy
Asthma or severe respiratory conditions
Open wounds or acute infections
Use of medications that affect thermoregulation or heart rate

Consult your physician before beginning cold exposure training, especially if any of the above contraindications apply or if you are unsure whether cold exposure is suitable for you.

3.3 Safety Rules

Never perform breathing exercises in or near water — risk of Shallow Water Blackout
Never practice cold exposure in water (ice bath, open water) alone — a companion should always be present
Stop the exposure immediately if you experience dizziness, nausea, numbness, confusion, uncontrollable shivering, or other warning signs
Start with short exposures and increase duration only gradually
Colder means shorter — lower temperatures require shorter exposure times

In an emergency: Call emergency services immediately (112 in Europe, 911 in the USA). Remove the affected person from the water, begin first aid if unconscious, and warm them up slowly. The App is not an emergency system and cannot place emergency calls.

3.4 Technical Safety Measures of the App

The App employs the following technical measures to support user safety:

Safety Acknowledgments: Before using any training program for the first time, the user must read and actively confirm program-specific safety information.
Breathing Safety Gate: Before using a breathing exercise for the first time, a separate safety notice about Shallow Water Blackout is displayed and must be actively confirmed.
Lead-In Safety Floor: Between a breathing phase and the start of the cold phase, the App enforces a minimum lead-in time (open water: 30 seconds, ice bath: 10 seconds) to allow the user to orient themselves before water contact.
Ready Gate:For water sessions, the App actively asks after the breathing phase: “Are you in position? Only enter the water when your head is clear.”
Auto-Stop: The session is automatically ended if the target duration is exceeded by more than 5 minutes (protection against forgetting).
Water Lock: During an active cold phase on the Apple Watch, the touchscreen is locked to prevent accidental touches caused by water.

These measures supplement but do not replace the user's personal responsibility (Section 3.5). Technical safety measures cannot fully prevent human error.

3.5 Personal Responsibility and Assumption of Risk

By using the App, you confirm that you:

are at least 18 years old
are aware of and understand the risks of cold exposure described in Section 3.1
have read the safety information and contraindications in the App and answer the safety acknowledgments displayed in the App truthfully
make your own decisions, taking into account your individual health condition, regarding whether, for how long, and under what circumstances you practice cold exposure
seek medical advice before beginning cold exposure if any of the contraindications listed in Section 3.2 apply
are solely responsible for the choice of location, duration, water temperature, and safety precautions (in particular the presence of a companion during cold exposure in water)

Cold Mastery provides a timer, training programs, and general information. The App does not make individual health decisions for you and cannot assess your personal health situation. The responsibility for the safe practice of cold exposure lies solely with you.

This personal responsibility does not release the Provider from its statutory obligations, in particular the obligation to inform about known risks (see Sections 3.1–3.3), to provide technical safety measures (see Section 3.4), and to provide the App free from defects that could lead to a health hazard (e.g., faulty timer function, faulty auto-stop).

4. Minimum Age

The use of Cold Mastery is only permitted for persons aged 18 years or older. By using the App, you confirm that you are at least 18 years old. The Provider is not obligated to verify users' ages but reserves the right to do so.

5. In-App Purchases and Subscriptions

Cold Mastery offers a free basic version as well as enhanced features through a paid subscription (Cold Mastery Pro).

Free Basic Version:Timer for cold showers, basic streak display, knowledge library, safety information, and the “Cold Starter” program.

Cold Mastery Pro (Subscription): All training programs, heart rate analysis, progress charts, extended statistics, breathing exercise voice guidance, and additional session types (ice bath, open water). The features included are described in the App Store and within the App.

Current prices are displayed in the App Store
Payment processing is handled exclusively through Apple (App Store)
Subscriptions renew automatically unless canceled at least 24 hours before the end of the current period
Cancellation is done through the subscription management in iPhone Settings or the App Store
Apple's Terms and Conditions apply additionally

Refunds are subject to Apple's policies.

Right of Withdrawal

The purchase and management of subscriptions are handled through the Apple App Store. The right of withdrawal for in-app purchases is governed by Apple's terms. You can request a refund directly from Apple at reportaproblem.apple.com. For digital content that is delivered immediately after purchase, the right of withdrawal may expire pursuant to § 356 para. 5 BGB (German Civil Code) if you have expressly consented to the early commencement of performance and acknowledged your awareness that your right of withdrawal expires upon such commencement.

6. Data Protection and Health Data

6.1 Principle

Cold Mastery is designed so that your data stays with you. A detailed description can be found in the Privacy Policy and the App Privacy Policy.

6.2 Health Data (HealthKit)

The App uses Apple HealthKit exclusively to:

Read the heart rate during an active session
Writeworkout entries (type: Mind & Body) after completing a session

Heart rate data constitutes health data within the meaning of Art. 9 para. 1 GDPR. Before the first use of the heart rate feature, the App informs you about the purpose and scope of the data processing. You are then asked for your explicit consent pursuant to Art. 9 para. 2 lit. a GDPR via the operating system's HealthKit permission prompt. You may revoke this consent at any time by withdrawing the HealthKit permission in your iPhone Settings (Settings → Privacy & Security → Health → Cold Mastery). Revocation does not affect the lawfulness of processing carried out prior to revocation.

The HealthKit permission is optional. The App also works without HealthKit access (timer without heart rate display). HealthKit data is not sent to external servers, not used for advertising, and not shared with third parties. Processing takes place exclusively on your device.

6.3 Data Synchronization

Session data (duration, time, program progress) is synchronized via your private iCloud to make it available between Apple Watch and iPhone. This is done through Apple's CloudKit infrastructure in your personal iCloud container. The Provider has no access to this data.

Heart rate aggregates are stored exclusively locally on the respective device and are not synchronized via iCloud.

6.4 Data Deletion

You can delete your data completely at any time:

Session data and program progress: Uninstall the App from Apple Watch and iPhone. The data in your private iCloud container is automatically removed. Alternatively, you can delete individual sessions directly in the App.
HealthKit data:Withdraw the HealthKit permission in iPhone Settings (Settings → Privacy & Security → Health → Cold Mastery). Workout entries already written to Apple Health can be manually deleted in the Health app.
Local heart rate aggregates: Deleted when the App is uninstalled.

Since the Provider has no access to your data, no deletion request to the Provider is necessary. For questions about data deletion, contact us at contact@coldmastery.com.

7. Availability, Updates, and Update Obligation

The Provider actively develops Cold Mastery further. Features and user interface may change with updates.

Updates (§ 327f BGB)

For the duration of an active subscription (Cold Mastery Pro), the Provider will provide updates necessary to maintain the contractual conformity of the App. This includes in particular security updates and bug fixes. Feature additions beyond the scope of services at the time of contract conclusion are voluntary and do not establish a claim to comparable additions in the future.

For the free basic version, the Provider will provide updates for the period that the user can reasonably expect. This period depends on the nature and purpose of the App and the circumstances of the individual case.

The user is responsible for installing available updates via the App Store. Damages resulting from failure to install available updates are not attributable to the Provider.

Material Feature Changes

The Provider will not remove features that are part of the Cold Mastery Pro service scope without a legitimate reason. Should a material Pro feature be discontinued (e.g., due to changes to Apple interfaces), the user will be notified at least 30 days in advance. In such cases, the user has a special right of termination effective at the time of the feature's removal.

System Requirements

The App requires:

Apple Watch with watchOS 10.0 or later
iPhone with iOS 17.0 or later

Compatibility with future operating system versions is intended but cannot be guaranteed.

8. Liability

8.1 Provider Liability

The Provider is liable without limitation for intent and gross negligence, as well as for damages resulting from injury to life, body, or health caused by a culpable breach of duty by the Provider.

In cases of simple negligence, the Provider is liable only for the breach of material contractual obligations (so-called cardinal obligations — obligations without whose fulfillment the contract would fail to achieve its purpose). In such cases, liability is limited to the typically foreseeable damage, but not exceeding the amount you have paid to the Provider in the last 12 months, with a minimum of EUR 50. In plain language: If we make an inadvertent mistake, we are liable up to the amount you paid us in the last year.

For the free version of the App, liability for simple negligence is excluded.

Important clarification for both versions (free and Pro): Liability for damages arising from injury to life, body, or health cannot be excluded or limited pursuant to § 309 No. 7a BGB — neither by the above limitation of liability nor by the liability cap. The Provider is liable without limitation for bodily injury and health damages caused by a culpable breach of duty, regardless of whether the user uses the free or Pro version.

Liability for indirect and consequential damages (in particular lost revenue) is excluded to the extent permitted by law. This does not apply to bodily injury and health damages.

8.2 Scope of Obligations: Cold Exposure

Cold Mastery is a tool for timekeeping and progress tracking. The Provider's obligation is limited to providing a functional App with the features described in Section 2, fulfilling the duty to inform pursuant to Sections 3.1–3.3, and providing the technical safety measures pursuant to Section 3.4.

The following is not part of the Provider's scope of obligations: the execution, supervision, or safeguarding of cold exposure itself. The App does not control environmental conditions and cannot assess the individual health condition of the user. In particular, the following lies outside the Provider's area of responsibility:

The user's decision to practice cold exposure — even in the presence of existing contraindications (Section 3.2)
Compliance with the safety rules (Section 3.3), in particular refraining from breathing exercises in or near water
The choice of location, duration, and water temperature
Ensuring the presence of a companion during cold exposure in water
Heeding warning signs from one's own body
The selection, maintenance, and safe use of personal equipment (in particular ice tubs, plunge pools, bathing pools). The Provider does not supply equipment and assumes no responsibility for its condition or safety

The Provider is liable, however, if:

it has breached its duty to inform and warn pursuant to Sections 3.1–3.3 (e.g., missing or incomplete safety information)
one of the technical safety measures described in Section 3.4 has malfunctioned (e.g., auto-stop fails to trigger, safety gate is bypassed, lead-in safety floor is not enforced)
another defect of the App (e.g., faulty timer function that fails to end a session; missing or incorrect safety warning) was the cause of the damage
mandatory law provides for liability (in particular the Product Liability Act pursuant to Section 8.3, liability for intent and gross negligence pursuant to Section 8.1, liability for bodily injury and health damages caused by a culpable breach of duty)

The burden of proof is governed by statutory provisions.

8.3 Product Liability

Liability under the German Product Liability Act (Produkthaftungsgesetz, ProdHaftG) remains unaffected. Software is considered a product within the meaning of the ProdHaftG. Product liability is strict (fault-independent) and cannot be contractually excluded or limited. The liability caps from Section 8.1 do not apply to claims under the ProdHaftG.

8.4 Heart Rate Data and Third-Party Hardware

The heart rate values displayed in the App originate from the Apple Watch's optical sensor and are provided via Apple HealthKit. The Provider does not warrant the accuracy, completeness, or medical usability of this data. The heart rate display serves self-observation purposes, not medical diagnostics.

The Provider is not liable for errors in the Apple Watch hardware or the HealthKit framework (e.g., inaccurate readings in cold conditions, sensor failures, delayed data transmission), as these are outside the Provider's sphere of influence. Claims arising from hardware defects should be directed to the respective device manufacturer (Apple).

9. Intellectual Property

All rights to the Cold Mastery App (source code, design, texts, graphics, audio files) remain with the Provider. The user receives a simple, non-transferable, non-sublicensable right of use for personal, non-commercial use of the App on their own Apple devices for the duration of the contractual relationship.

Decompilation, reverse engineering, or redistribution of the App is not permitted unless mandatorily allowed by law.

10. User Obligations

The user agrees to:

Not use the App for unlawful purposes
Not circumvent or manipulate security mechanisms of the App
Observe the safety information in the App (in particular Safety Acknowledgments and Breathing Safety Gate)
Not make the App accessible to minors

11. Changes to These Terms

The Provider may amend these Terms of Use with effect for the future, insofar as this is necessary for objectively justified reasons (changed legal situation, new features, security reasons).

Changes will be announced at least 30 days in advance — by email (where an email address is available) or by notice in the App. With each change, you will be asked for express consent when you next launch the App. Without renewed consent, the previous terms continue to apply. If you do not agree to the amended terms, you may continue using the App under the last accepted version until you cancel your subscription or install an update that requires the new terms.

12. Support and Contact

For questions, issues, or feedback, you can reach the Provider at contact@coldmastery.com. The Provider endeavors to respond within 5 business days. There is no entitlement to 24/7 support or to a response within specific deadlines.

For safety-related issues (e.g., an app defect that could pose a health risk), please contact contact@coldmastery.comwith the subject line “Safety.” The Provider prioritizes such reports.

13. Consumer Dispute Resolution

The Provider is neither obligated nor willing to participate in dispute resolution proceedings before a consumer arbitration body.

14. Final Provisions

The laws of the Federal Republic of Germany shall apply, excluding the UN Convention on Contracts for the International Sale of Goods (CISG). Statutory provisions on jurisdiction apply.

Should individual provisions of these Terms of Use be or become invalid, the validity of the remaining provisions shall not be affected. The invalid provision shall be replaced by the applicable statutory provisions (§ 306 para. 2 BGB).

Transfer of Contract: The Provider may transfer the contract to a legal successor in the course of a business sale or transformation (e.g., incorporation into a UG or GmbH), provided that the performance of services is not materially impaired thereby. The user will be notified at least 30 days before the transfer takes effect by email or in-app notice. In the event of a contract transfer, the user has a special right of termination effective at the time the transfer takes effect.

Last updated: June 17, 2026