The arctic sleeping bag is used in extreme cold weather. It consists of two down and feather filled cases, the inner one being a regular mountain sleeping bag. The outer case has a hood and a full mummy shape and is closed with snaps. The two cases may be tied together by means of the tapes at the foot of each bag. When the weather is only moderately cold and it is important to cut down on weight, the outer case may be left at the case. It weight 12.00 lbs.
The mountain sleeping bag is a mummy-shaped, down and feather-filled sleeping bag, made in regular and large size, in which an over-lapping tube construction prevents the entry of cold air at the stitching. The shape and design gives maximum warmth with minimum weight. A waterproof bag is provided for protecting the rolled bag. The regular bag weighs 5.75 lbs. The large bag weighs 6.00 lbs.
The extreme cold weather sleeping bag is for use in locations where mean monthly temperatures are below +10°F.
The intermediate cold weather sleeping bag is for use in locations where mean monthly temperature ranges from +45°F to +10°F.
The 3 season sleep system (3S) is a single sleeping bag system that is lighter in weight and provides increased environmental protection for all environments except extreme cold weather.
The Extreme Cold Weather Sleep System (ECWSS) will provide environmental protection between +40°F and -45°F (+5°C and -46°C) and is intended to be used with the foam sleeping mat.
The Intermediate Cold Weather Sleeping System is an ICW version of the extreme cold weather sleeping system.
The Modular Sleep System is designed to insulate the user in environments ranging from mild weather to extreme cold weather.
The M-1949 arctic outer shell sleeping bag is designed to fit over the mountain sleeping bag in temperatures of 14°F and below.
The M-1949 mountain sleeping bag is intended for use in locations where temperature ranges from 14 to 50°F.
Commercial item description A-A-55116 covers the requirements for one type and size of sleeping bag with hood.
Commercial item description A-A-55262 covers a modular sleeping bag system that consists of a patrol sleeping bag, an intermediate cold weather sleeping bag and a compression stuff sack to carry the complete system.
Military specification MIL-B-10721 covers the requirement of the M-1949 mountain and arctic sleeping bag.
Military specification MIL-B-830 covers the requirement of the M-1949 mountain and arctic sleeping bag.
Military specification MIL-S-43880 covers the requirement for one type and size of sleeping bag with hood for extreme cold conditions.
Military specification MIL-S-44016 covers the requirements for one type and size of sleeping bag with hood for intermediate cold conditions.
Military specification MIL-S-44309 covers sleeping bags for use as part of the extreme and intermediate cold weather sleeping systems.
Military specification MIL-S-44361 covers a complete extreme cold weather sleeping bag system.
Military specification MIL-S-44429 covers a complete intermediate cold weather sleeping bag system.