Best Military Sleep System: Sleeping Bag Facts & Info (2023)
The Military Sleep System, also known as the Military Modular Sleep System (MSS), is a sleeping bag system designed to provide a scalable survival capability from mild to extremely cold, life-threatening environmental conditions.
The modular sleep system is designed in layers to provide pockets of air-trapping insulation. The systems layers consist of an outer camouflaged and waterproof, breathable Gore-Tex bivy sack and two inner mummy-style sleeping bags (patrol and intermediate cold weather), which, when combined, provide environmental protection capability down to -50°F (-40C). A compression-style stuff sack is also included to compress the entire system into one cubic foot are for ease of storage and transportation.
Disclaimer: This article contains affiliate links that I may receive a small commission for at no cost to you if you choose to purchase a product through a link on this page.
This rugged, cold-weather-defeating system, while designed as a sleeping bag for the military, is a great option for anyone intent on facing and surviving some of the harshest conditions Mother Nature has to offer. That’s why I picked up my Military Sleep System on Amazon.
What are the Parts of the Military Sleep System (Sleeping Bag)
The modular sleep system is designed as a layered and rugged defense against harsh environments. It is a scalable sleep system of independent parts that, depending on the circumstances, can be configured by the user to address a wide array of environmental threats and hazards.
Sleeping Bag – Patrol
The patrol bag is designed for use in temperate climates ranging in temperature down to 30°F.
The patrol sleeping bag is made of lightweight, highly compressible, synthetic, migration-free insulation. It can be thought of as similar to a warm-weather sleeping bag. The ICW portion of the modular sleep system is free from cold spots and includes a well-insulated, anatomically designed foot box.
Patrol bags have a reversible double pull slider (zipper) that provides for top or bottom sleeping bag ventilation. The bag is equipped with a draft flap to prevent heat loss through the zipper.
The US military patrol bag includes an adjustable insulated hood to help control heat loss and stay warm.
Sleeping Bag – Patrol (Specs):
- Temp Range: Down to 30°F (-1C)
- Internal Length: 90 to 92 inches
- Shoulders: 36 to 37 inches
- Top of Foot Box: 22 to 24 inches
- Weight: 3 lbs
Sleeping Bag – Intermediate Cold Weather (ICW)
The intermediate cold weather bag is designed for use in cold weather climates ranging between 30°F to -10°F.
As with the patrol bag, the ICW sleeping bag is made of lightweight, highly compressible, synthetic, migration-free insulation. The ICW portion of the modular sleep system is free from cold spots and includes a well-insulated, anatomically designed foot box.
The intermediate bag includes a chest collar that is sewn along the inside of the sleeping bag, preventing drafts from entering through the hood.
As with the patrol bag, the ICW sleeping bag includes an adjustable insulated hood to help retain body heat.
Sleeping Bag – Intermediate Cold Weather Bag (Specs):
- Temp Range: 30°F to -10°F (-1C to -23C)
- Internal Length: 85 to 87 inches
- Shoulders: 35½ inches
- Top of Foot Box: 23 inches
- Weight: 4 lbs
Sleeping Bag – Extreme Cold Weather (ECW)
This is not a separate piece of sleep system gear, such as a single cold-weather sleeping bag. Rather, the ECW is the term used when the Sleeping Bag – Patrol is joined to the Sleeping Bag – ICW. Together these two joined sleeping bags create the Sleeping Bag – ECW.
Sleeping Bag – Extreme Cold Weather (Specs):
- *Temp Range: -10°F to -50°F (-23C to -45C)
- Internal Length: 85 to 87 inches
- Shoulders: 35½ inches
- Top of Foot Box: 23 inches
- Combined Weight of Sleeping Bags: 7 lbs
*Note: The ECW bag configuration insulates to at least -30°F for users wearing proper clothing, such as the military’s polypropylene expedition weight undershirt, drawers, and socks. It is rated to -50°F for a user wearing various layers of ECW clothing in extremely cold weather (Source).
Outer Gortex Bivy Cover
The official nomenclature of the bivy cover is Cover, Extreme Cold Weather Sleeping System (ECWSS). The bivy cover creates a vapor-permeable moisture barrier that provides environmental protection from wind and water. The ECWSS can be used with each of three MSS configurations patrol, intermediate, or when combined into the ECW configuration.
Outer Gortex Bivy Cover (Specs):
- Length: 83 inches
- Widest Width: 35 inches
- Narrowest Width: 13 inches
- Weight: ~1½ – 2 lbs
Stuff Sack – Compression
The entire military sleeping bag system is designed to be stored and transported within a cylindrical compression stuff sack. The stuff sack is engineered to provide storage and protection for the combined ECW system. Its straps and buckles are designed for users wearing gloves and mittens and are capable of compressing the modular sleep system into a one cubic foot area.
The compression stuff sack is made from 200 denier plain weave, water-resistant nylon. It includes six one-inch wide webbing straps with ladder lock buckles to provide leverage for compressing the sleeping bag system.
Compression Stuff Sack (Specs):
- Length: 28 – 30 inches
- Widest Width: 12 – 14 inches
- Weight: ~.75 lbs
How to use Military Modular Sleep System (Sleeping Bag)
My Thoughts on the Military Modular Sleep System
The MSS is military tough. It offers excellent protection against the environment and does a great job of meeting your survival needs. A modular sleep system is a scaleable, functional, and durable piece of survival gear every preparedness-minded outdoor enthusiast should own.
I picked my sleep system on Amazon and was so happy with it that I picked up a second.
Check it out today!
Additional Resources:
- 21+ Best Winter Safety Tips For Cold Weather Survival
- Best Emergency Sleeping Bags | Guide and Review (2023)
- Layering Clothes: How to Layer Clothes to Stay Warm and Dry
- Kamik Boots: Review of My Winter Boots (2022)
Stay safe,
Don't Miss Out!
Join the thousands of people who rely on Mind4Survival preparedness advice by subscribing to our FREE newsletter.
- Practical preparedness information
- Zero Spam
- < 0.25% of people unsubscribe
Join Mind4Survival!
Stay informed by joining the Mind4Survival! 100% Secure! 0% Spam!
Follow Us!
Affiliate Disclosure
Mind4Survival is a free, reader-supported information resource. If you make a purchase through our link, we may, at no cost to you, receive an affiliate commission.
I procured for these systems just the other day from a thrift store. Someone donated them and I reaped the benefit of deep discounts. They are high quality like I remember in my time in the service. They are not great for folks over 6’3″. But for the rest of us they are perfect for almost all weather.
Great job! Thanks for your feedback!