User Review: U.S. Armed Forces Modular Sleep System MSS
Temperature Rating: -30F
As long as there are Modular Sleep Systems (MSS) available online and through surplus markets, I won't be using, nor recommending the use of any other system.
The MSS is just that, a SYSTEM. It's modular and will adapt to whatever environment you may find yourself in.
The quality of the materials used and manufacture of each component is high. This is definitely hard-use kit.
The bivy is excellent, and I can think of one particular night mission where we bedded down in the dark on a rainy night and woke up in the middle of a small stream...still entirely dry. The bivy is a shelter in and of itself, cutting wind and water out of the equation completely.
The patrol bag is nice and light, and can compact well. Even though it is the light bag, it is still a very warm sleeping bag. With me living in the American Southwest, the patrol bag is more than sufficient for most outings.
The intermediate bag is larger and heavier, but the warmth it provides makes it all worth the expense. During the winter, knowing how cold the desert can be at night, this is usually my bag of choice.
When the entire system is integrated (patrol bag, intermediate bag, bivy) you have an extremely warm sleeping system, more than capable of handling temperatures below freezing.
I'll be the first to admit that the MSS isn't the latest or lightest wizbang sleeping bag, but it's affordable, extremely capable, and the modularity lends flexibility to your load. Bring only what you need...