Sleeping bags must be light, comfortable, easy to compress, and warm to the climate of the camp. The type, quantity, thickness (bulkness), size (not fit), style and structure of the insulation layer affect the warmth effect. Sleeping bags are divided into summer, three seasons, and winter expeditions. Manufacturers classify their sleeping bags, set the level of comfort, and indicate the lowest temperature at which they work. (The sleeping bags without these markings advise everyone not to consider it).
The sleeping bag should have a cover for the head and a drawstring design to prevent the escape of hot air from the head. Some sleeping bags are also equipped with isolation collars to keep warm shoulders; some sleeping bags have additional insulation on important parts such as the chest or feet to enhance warmth; from the top to the end of the sleeping bag, the zipper must be attached with a windshield to prevent cold. The wind breaks in from the zipper gap. The two-way zipper is convenient for discharging more than hot air, and the anti-twisting strip is attached to the back of the zipper.
The lightest and warmest sleeping bag style is called the mummy bag. It is gradually narrow from top to bottom. The head has a cover. The small mouth is exposed with a drawstring. The mummified type should fit, too small and fluffy. To keep warm; too much heat is easy to lose. Another type of envelope-style sleeping bag is as wide as it is from top to bottom; some designs can be opened as a quilt in summer and not as hot as inside.
Compared with synthetic fiber-filled sleeping bags, the down-filled sleeping bag provides greater warmth, compressibility and durability, and is soft and comfortable. However, pure down sleeping bags are more expensive, and once wet, they will lose their warmth. It is not suitable for use in rainy or humid climates. Please put the sleeping bag into the waterproof cover before use.
If you often work in rainy areas, or if the camp is wet and mild, it is best to choose synthetic fiber (such as hollow cotton) sleeping bag. The biggest advantage of synthetic fiber is that it can maintain a certain degree of bulk after damp, can be dried quickly, and the price is relatively low. The disadvantages are heavier, less compressible, and larger in volume (requires a compression bag to achieve better compression), and gradually loses bulkiness as time goes by. But now there are new designs of hollow cotton (such as seven-hole cotton) sleeping bags, no matter from the bulkiness and compressibility than the previous (four-hole cotton) has a great improvement, the effect is straight down to the down sleeping bag. The cleaning and maintenance of the sleeping bag should be done according to the instructions of the label. The sleeping bags of different materials are very different.