Disclaimer

Last Updated: January 15, 2026

Nature of This Tool

The UL Sleep Calculator is a free educational tool designed to help ultralight backpackers estimate their sleep system's temperature performance. It is NOT a substitute for:

• Professional outdoor education or certification courses
• Personal experience and field testing
• Expert advice from qualified guides or instructors
• Manufacturer specifications and recommendations
• Common sense and sound judgment

Accuracy and Reliability of Calculations

Estimates, Not Guarantees

All calculations provided by our Website are estimates based on general formulas and principles from the ultralight backpacking community. These estimates:

• Are not scientifically validated: Our formulas are derived from community wisdom and user feedback, not laboratory testing or peer-reviewed research
• Vary by individual: Personal factors including metabolism, fitness level, body composition, fatigue, hydration, nutrition, and acclimatization significantly affect cold tolerance
• Depend on conditions: Actual performance varies based on humidity, wind, precipitation, altitude, shelter quality, ground conditions, and other environmental factors not captured by our calculator
• Rely on accurate inputs: Results are only as accurate as the information you provide. Manufacturer ratings may be optimistic or use different testing standards (EN 13537, ISO 23537, proprietary methods)

Manufacturer Specifications

Temperature ratings provided by gear manufacturers (quilts, sleeping bags, sleeping pads) are based on standardized testing conditions that may not reflect real-world use. Factors affecting actual performance include:

• Testing methodology (EN Comfort vs. Limit ratings)
• Age and condition of gear (loft degradation over time)
• Proper use and fit (proper sizing, draft collar usage, etc.)
• Layering with other insulation
• Shelter type and wind protection

Inherent Risks of Outdoor Activities

Backpacking, camping, and other outdoor activities involve inherent risks including but not limited to:

• Hypothermia: Life-threatening condition caused by prolonged exposure to cold
• Frostbite: Tissue damage from freezing temperatures
• Altitude sickness: Physiological effects of high elevation
• Weather hazards: Lightning, flash floods, avalanches, extreme temperatures
• Wildlife encounters: Bears, snakes, insects, and other animals
• Injuries: Falls, sprains, cuts, and other physical injuries
• Getting lost: Disorientation, navigation errors

You assume all risks associated with outdoor activities when you use information from this Website.

No Professional Advice

The content on this Website is for general informational and educational purposes only and does not constitute:

• Professional outdoor guiding or instruction
• Medical advice or recommendations
• Safety certification or endorsement
• Personalized gear recommendations (unless explicitly stated)
• Guarantee of fitness for any particular purpose

Always consult with qualified professionals, take appropriate training courses (wilderness first aid, navigation, etc.), and gain experience in controlled environments before attempting challenging outdoor activities.

Personal Responsibility

You are solely responsible for your own safety and well-being when engaging in outdoor activities. This includes:

• Verifying the accuracy of any calculations or information from this Website
• Testing your gear in safe conditions before relying on it in the backcountry
• Checking weather forecasts and being prepared for changing conditions
• Carrying appropriate safety equipment (first aid kit, emergency shelter, communication device, etc.)
• Informing others of your trip plans and expected return time
• Knowing your limits and turning back when appropriate
• Having contingency plans for emergencies

Third-Party Content and Links

Our Website may contain links to third-party websites, gear reviews, blog posts, or other content. We are not responsible for:

• The accuracy, completeness, or reliability of third-party content
• The safety or performance of third-party products
• Third-party websites' terms of service or privacy policies
• Any damages or losses resulting from your use of third-party websites or products

Affiliate Disclosure: We may earn commissions from qualifying purchases made through affiliate links. These commissions do not affect the price you pay and do not influence our editorial content. We only link to products we believe may be useful to our users.

Limitation of Liability

TO THE MAXIMUM EXTENT PERMITTED BY LAW, UL SLEEP CALCULATOR, ITS OWNERS, OPERATORS, AFFILIATES, AND CONTRIBUTORS SHALL NOT BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, CONSEQUENTIAL, OR PUNITIVE DAMAGES, INCLUDING BUT NOT LIMITED TO:

• Personal injury, illness, or death resulting from outdoor activities
• Property damage or loss
• Reliance on calculations, estimates, or recommendations from this Website
• Errors, omissions, or inaccuracies in content
• Website downtime or technical issues
• Use of third-party products or services

Some jurisdictions do not allow the exclusion or limitation of liability for consequential or incidental damages, so the above limitations may not apply to you.

No Warranty

This Website and all content are provided "AS IS" and "AS AVAILABLE" without warranties of any kind, either express or implied, including but not limited to:

• Warranties of merchantability or fitness for a particular purpose
• Warranties of accuracy, completeness, or reliability
• Warranties of uninterrupted or error-free operation
• Warranties regarding the results of using the Website

Recommended Safety Margin

We strongly recommend adding a safety margin to all calculations:

• Add 5-10°F (3-6°C) to your comfort temperature for general use
• Add 10-15°F (6-8°C) for critical trips, solo travel, or when consequences of failure are severe
• Always carry backup warmth such as an extra insulating layer or emergency bivy
• Test your system in controlled conditions before committing to challenging trips

Updates and Changes

We reserve the right to modify, update, or discontinue any aspect of this Website at any time without notice. We may update this Disclaimer periodically, and your continued use of the Website constitutes acceptance of any changes.

Questions and Contact

If you have questions about this Disclaimer or our Website, please contact us at:

Email: safety@ul-sleep-calculator.com

Website: ul-sleep-calculator.com

For full terms and conditions, please see our Terms of Service and Privacy Policy.