How to choose a sleeping bag for outdoor activities

　　What are the criteria for choosing an outdoor sleeping bag?

　　1. Minimum temperature at night

　　①If the minimum temperature at night is higher than 25 degrees, you can use a fleece sleeping bag. Of course, you can also use a thin envelope-style cotton sleeping bag to cover your stomach to avoid cold stomach.

　　②When the minimum temperature at night is higher than 15 degrees, you can use an envelope-style cotton sleeping bag with 200-250 grams of filling.

　　③When the minimum temperature at night is higher than 5 degrees, you need to use a 300g-filled mummy-style cotton sleeping bag, or a 400g-filled down sleeping bag.

　　④When the minimum temperature at night is higher than -5 degrees, you need to use a mummy-style cotton sleeping bag with a filling of 350g-400g. Or use a down sleeping bag filled with more than 700 grams.

　　⑤When the minimum temperature at night is higher than -10 degrees, you need to use a 350g-400g filled mummy-style cotton sleeping bag plus a fleece sleeping bag liner to obtain better warmth. Or just use a down sleeping bag filled with more than 1000 grams.

　　⑥When the minimum temperature at night is higher than -15 degrees, only down sleeping bags filled with more than 1,200 grams can be used.

　　⑦When the minimum temperature at night is higher than -20 degrees, only down sleeping bags filled with more than 1500 grams can be used.

　　2. Sleeping bag, comfortable and low temperature

　　The most important indicator of a sleeping bag is the temperature scale, also called comfortable low temperature. Comfortable low temperature means that when the outside temperature drops to a certain temperature, most people feel comfortable using this sleeping bag. If the temperature drops further, they will feel cold. There are two ways to mark the comfortable low temperature on sleeping bags:

　　①Marking an absolute temperature, such as -10 degrees, indicates that the comfortable low temperature of the sleeping bag is -10 degrees.

　　②Mark the temperature range, transitioning from red to green or blue, for example, red starts at 5 degrees, transitions to light green at 0 degrees, and transitions to dark green at -5 degrees. The meaning of this temperature representation is: 5 degrees is warm, 0 degrees is suitable, and -5 degrees feels very cold. The comfortable low temperature of this sleeping bag is 0 degrees.

　　How to choose an outdoor sleeping bag?

　　1. Sleeping bag filler

　　There are two main types of fillings, down and chemical fiber cotton, and there are also single-layer fleece sleeping bags. Down is divided into duck down and goose down. Under the same conditions, goose down is slightly warmer than duck down.

　　①Filling weight, such as 400g goose down sleeping bag, 1100g duck down sleeping bag, this weight does not refer to the weight of the sleeping bag, but refers to the net weight of the down filling.

　　②Down content, down is composed of pinnae and velvet. The pinnae has a supporting effect, and the warmth mainly comes from fine down. The velvet content is expressed as a percentage. For example, 80 velvet means that the velvet content in 100 weight units is 80 units. Duck down generally has a maximum down content of 85 to 90%, and goose down has a down content of 90 to 95%.

　　③The expansion degree of down refers to how many cubic inches an ounce of down has under 68.4 grams of pressure. The higher the expansion degree of down, the better the thermal insulation performance of down. Generally, the expansion degree of domestic duck down is around 450, and the expansion degree of domestic goose down is from 450 to 600.

　　④Oxygen consumption index and cleanliness

　　Down needs to go through multiple professional cleaning and degreasing procedures. Some vendors make finished products after a little cleaning of primary down. These products cannot be used at all. A simple identification method is to knock the finished products with a wooden stick, dust will leak out, and there will be an odor if you smell it. If you wash it, there will be a smell in the water.

　　2. Internal and external materials

　　Ordinary cotton sleeping bags use polyester or nylon materials, and polyester and nylon cloths have differences in density and texture, which I won’t go into detail here. Down sleeping bags have very high requirements for internal and external materials, and nylon materials with a density of at least 230T are required to ensure down protection. High-weave pure cotton or polyester cotton can also prevent lint, but it is heavy and has poor compressibility, so it is generally not used in high-end sleeping bags.

　　Many domestic nylon cloths are not dense enough to prevent lint. Manufacturers use coatings to prevent lint, which is a very unscientific approach. Because the inner and outer materials of a down sleeping bag need to have good breathability, otherwise the moisture emitted will accumulate inside the sleeping bag, greatly reducing the warmth retention of the down.

　　3. Functional design

　　①Mummy style is also called mummy style or mummy style. This kind of sleeping bag has wide shoulders and narrow feet. The shoulder width is generally 75 to 85 cm, and the foot width is 45 to 55 cm. The Mammy sleeping bag is the sleeping bag shape that can achieve the best thermal insulation effect under the same weight and is suitable for use in cold seasons.

　　②As the name suggests, the envelope-style sleeping bag has a shoulder cloth as wide as the feet, like an envelope. This type of sleeping bag is looser and suitable for warm summer seasons and people with a wide body shape.

　　③The hybrid sleeping bag is a combination of the first two, with a foot width between 55 and 65 centimeters.

　　④The internationally popular sleeping bag is a small square hat with a streamlined body shape (the widest part is not at the collar, but at the shoulders and elbows). The previous large round hat not only added weight, but was also not conducive to warmth.

　　4. Packaging and accessories

　　The best sleeping bag packaging is an Oxford cloth compression bag, which can be large or small, strong and durable.

　　99 warm reminder from enthusiastic doctors, Sometimes you will find particularly cheap down products on the market, such as a down jacket for 100 yuan or a duck down sleeping bag for 150 yuan. Such products are generally not available.