Comparison Naturehike LD350 vs Naturehike M400

The season for which the sleeping bag was originally intended. Note that many models are designed for more than one season — winter and spring / autumn or spring / autumn and summer ; there are even all-season products. However, anyway, when buying, it is worth clarifying not only this nuance, but also the specific temperature characteristics of the selected model (see below).

In general, the assignment of a sleeping bag to one or another seasonality largely depends on how the manufacturer positions this model. However, in each category there are some common features, here they are:

— Winter. Sleeping bags suitable for winter usually meet the following minimum requirements: at least the temperature of the comfort limit in them should be below zero, and if it is higher, then the extreme temperature should be low enough (-20 °C or less). Also, a sleeping bag is definitely considered winter if its comfort temperature is below -5 °C.

— Spring/Autumn. Sleeping bags designed for the off-season should be comfortable enough both in warm weather and in case of sudden frosts. Therefore, the comfort temperature in them can be quite low — up to -5 °C inclusive. On the other hand, there are also combined "off-season-summer" models, where the extreme temperature is as much as +10 °C. So the specific characteristics of such a...sleeping bag should be specified especially carefully.

— Summer. A summer sleeping bag should provide comfort at high temperatures, so many models from this category have a comfort t ° of the order of +15 °C, or even higher. At the same time, summer seasonality can also be indicated for models with lower comfort temperatures (even below zero). In such cases, the manufacturer proceeds from the fact that if it is hot in the sleeping bag, you can open up or undress (recall, the temperature regimes are indicated for a person in thermal underwear).

Since a sleeping bag is a travel outfit, its weight can be one of the key characteristics. Two points should be taken into account here: firstly, more insulation usually requires more material and increases weight, and secondly, warm models with low weight are much more expensive than heavier options with the same temperature characteristics.

Also, when choosing a sleeping bag, you should decide what exactly you are buying it for. If we are talking about picnics, festivals and other simple trips to nature without long walks, or if you plan to carry equipment by car, you can not pay much attention to weight, focus on other characteristics. If you plan to go on long hiking or cycling trips, you should choose a model with a minimum weight.

As for specific numbers, most modern sleeping bags are in the range of 1.1 – 1.5 kg or 1.6 – 2 kg, although there are quite a few ultra-light models — 1 kg or less. An indicator of 2.1 – 2.5 kg is already considered quite significant, and a weight of 2.6 – 3 kg or more is found mainly in two types of sleeping bags: separate expeditionary models with a high degree of insulation, as well as double products.

Some manufacturers use their own criteria to designate this temperature; however, they predominantly use the accepted standard. According to it, the comfort temperature is the lowest ambient temperature at which a man in thermal underwear can comfortably sleep in a sleeping bag all night (a minimum of 8 hours) without waking from the cold, in a relaxed position. Naturally, actual comfort will depend on the individual's body and preparation.

Some manufacturers use their own criteria to designate this temperature, but predominantly, the common standard is used. According to it, the comfort temperature is the lowest ambient air temperature at which a woman in thermal underwear can sleep comfortably, without waking up from the cold, in a sleeping bag throughout the night (at least 8 hours) in a relaxed position. Of course, actual comfort will depend on the individual's body characteristics and specific person's preparation.

Extreme temperature of this sleeping bag.

Some manufacturers use their own criteria to designate this temperature, but predominantly a commonly accepted standard is used. According to it, the extreme temperature is the temperature at which a prepared female traveler with a sturdy build (height 160 cm, weight 60 kg) in thermal underwear can spend the night (at least 6 hours) in the sleeping bag in a heat-conserving position ("curled up") without the risk of hypothermia. These criteria are based on the considerations that a person's tolerance to cold depends on gender (women feel colder than men), body build (slim people are more sensitive to cold), and preparation. It should be noted here that if you are not accustomed to camping conditions, the extreme temperature should be considered as the lowest temperature at which the sleeping bag can be used without life risk. Comfort is not guaranteed, and there is a high chance of hypothermia; therefore, in such temperatures, not only quality thermal wear might be needed but also additional insulation.

— Polyester. Synthetic material. The advantages of polyester are good water-repellent properties, strength and durability. On the other hand, it, like many synthetic materials, is not very pleasant to the touch and can cause some discomfort, especially in warm weather, when you can sleep in one underwear.

— Flannel. Natural fabric of cotton or wool type. It is pleasant to the touch and quite versatile: it is well suited for both warm and even hot weather (due to naturalness), and for cold weather (it saves heat well). The disadvantages of flannel are the tendency to wear (the appearance of "pellets") with prolonged use, as well as high hygroscopicity — the fabric absorbs moisture well and dries for a long time.

— Cotton. Cotton, like flannel, belongs to natural materials and is well suited for use in hot weather, however, the thermal insulation of such an “insider” is significantly lower. Among the other advantages of cotton, it is worth noting strength, resistance to water, temperature extremes and light (although it may turn yellow in the light); of the shortcomings is hygroscopicity (although less than that of flannel).

— Polycotton. Combined material based on a combination of polyester and cotton in varying proportions. Designed to combine the advantages of both materials. Polycotton is strong, durable,...has good water repellency while being nicer to the touch than pure polyester and is better for use in hot weather.

— Fleece. Synthetic material, widely used for the manufacture of warm clothing. It has the appropriate characteristics, in particular it is light, retains heat well, including in a wet state; passes the evaporated moisture ("breathes"), does not accumulate it and dries quickly. At the same time, fleece is somewhat less durable than the rest of the synthetics, and also catches fire easily, therefore it requires some caution in the presence of fires and other sources of fire nearby.

— Nylon. A synthetic material similar in most properties to polyester (see above), but somewhat less durable and resistant to moisture (tends to stretch when wet). It is used mainly in inexpensive models of sleeping bags.

— Synthetic. Insulation based on synthetic fibers, usually polyester. The main advantage of this material is its resistance to moisture: when wet, it not only retains its strength but also continues to maintain most of its thermal insulation properties, and drying such a sleeping bag is easy — when hung, most of the water drains off in the first few minutes. Additionally, synthetic materials do not cause allergies. On the other hand, the overall thermal insulation of such sleeping bags is somewhat lower than that of down, and prolonged storage in a compression sack further reduces it due to fiber compression. Modern sleeping bags may use short and long synthetic fibers; the first option generally has better characteristics, while the second is significantly cheaper.

— Down. Natural duck or goose down is mainly used in premium-class sleeping bags. With smaller dimensions and weight than synthetic materials, this material has significantly better thermal insulation. On the other hand, down is very sensitive to moisture, losing its insulating properties when wet and drying quite slowly. Therefore, many down bags have special water-repellent coatings and/or come with synthetic waterproof covers. The prices of such sleeping bags are noticeably higher than synthetic ones. Overall, down bags are considered suitable primarily for winter hikes and mountain climbing. It is also worth noting that people prone t...o allergies should use this material with caution.

— Combined. This category includes sleeping bags based on high-quality synthetic materials designed to replace down (see above). Such materials are comparable to down in terms of insulation, lightness, and compactness, while lacking the main drawback — sensitivity to moisture: they do not absorb water and dry significantly faster. However, the price of such sleeping bags is accordingly higher.

— Cotton. Sleeping bags with cotton filling provide comfort and good thermoregulation due to the natural properties of the material. Cotton is soft, hypoallergenic, and pleasant to the skin, making these bags suitable for people with sensitive skin. However, cotton filling is less effective at retaining heat compared to synthetic materials and dries slowly when wet, making it less practical for hiking in damp or cold weather. These bags are more suitable for camping in dry and moderate climates.

In addition to the standard elements of the sleeping bag design in the form of a hood(can also be removable), headrest, inner pocket, thermal zipper roller, drying loop and the ability to zip up, there may also be a light-accumulating loop, a compartment for a pillow, a warm collar, a fastener at the feet, a mosquito net, a compression bag.

— Hood. A classic hood that covers the head of a person in a sleeping bag. This detail provides additional thermal insulation: firstly, due to the fact that it protects the neck, the back of the head and most of the head from the cold, and secondly, due to the reduction of the space through which heat can escape from the sleeping bag.

— Removable hood. A type of hood (see above) with the ability to remove it at the user's discretion. This makes the sleeping bag more versatile: in warm weather, you can remove the hood so that it does not interfere, and when it gets cold, you can fasten it back, providing maximum protection from the cold.

— Headrest. A lining without the ability to...tighten around the head, used for more comfortable placement on the sleeping place and to reduce heat loss through the head on cool nights. Used in sleeping bags of the blanket type. Headrests for sleeping bags are often rectangular in shape and have an integrated pillow.

— Mosquito net. A protective net that covers the face of a person lying in a sleeping bag. Such a net holds back mosquitoes and other annoying insects, while at the same time air passes through it freely.

— Leg closure. A separate closure located in the leg area of the sleeping bag. In warm weather, this closure can be unzipped without opening the entire bag — this way, your legs won’t sweat in the sleeping bag, and the rest of your body will remain covered. The closure can be either a zipper or a drawstring.

— Zip-up capability. The ability to connect the sleeping bag to another bag (bags), creating a sleeping place for several people (usually for two, but in some models it is possible for more). This function will be useful in case of cold weather: it can be difficult to warm up in a sleeping bag alone, but several people in one bag additionally warm each other. When choosing, it is worth considering that sleeping bags from different manufacturers (and even different models from the same manufacturer) may differ in design and size of zippers. So if you are going to use this function, you should pay special attention to compatibility.

— Light-accumulating loop. A loop on the zipper puller that has an insert made of light-accumulating material. This material “charges” during daylight hours and glows itself in the dark. Thus, the fastener can be found even in complete darkness; this provides not only comfort, but also additional safety in case you need to quickly get out of your sleeping bag.

— Inner pocket. A pocket located on the inside of the sleeping bag. This compartment is convenient for storing documents and other small but valuable items: it is not easy to steal them from an inner pocket, and the likelihood of losing the contents while sleeping is reduced to almost zero.

— Pillow compartment. A special compartment in which you can place a pillow or its substitute (for example, a bag of spare clothes) without fear of damaging or stretching the sleeping bag itself.

— Insulated collar. An additional collar that tightly covers the neck of the person in the sleeping bag. This provides additional sealing and maximally blocks the access of outside air to the body and legs. In addition, the collar helps the head and neck warm up faster.

— Insulated zipper (fastener). A system of zipper insulation, usually in the form of a heat-insulating roller or strip along the entire fastener. The zipper is one of the weakest points of a sleeping bag in terms of thermal insulation, and therefore when choosing a sleeping bag for low temperatures (especially an expedition one, see "By Purpose"), it is worth paying attention to the presence of a thermal roller, preventing heat loss.

— Drying loops. Special loops that allow you to hang your sleeping bag to dry — on a rope or even on tree branches. Note that experienced tourists recommend “ventilating” your sleeping bag every morning, as moisture inevitably accumulates in it overnight; and in any case, a wet sleeping bag dries much faster when suspended than when lying on the ground.

— Compression bag. A bag-cover for storing and carrying a sleeping bag, equipped with compression straps. Such straps allow you to strongly compress the cover with the sleeping bag packed in it, maximally “squeeze out” the air from the inside and thus reduce the size of the package - this significantly simplifies transportation. However, we note that you cannot keep the sleeping bag compressed all the time; for long-term storage, the straps should be loosened.

Dimensions of the sleeping bag when unfolded. Although the designation of sizes includes the traditional three numbers, in the case of sleeping bags there is a peculiarity: these numbers do not indicate length, width and height (depth, thickness), but length, width at the shoulders and width at the legs. For example, the designation 220x80x50 means 220 cm in length, 80 cm in width at the shoulders and 50 cm in width at the legs (for more information about sleeping bags with different widths, see “Type”).

It is believed that the optimal sleeping bag sizes are:

- Length - 15-20 cm more than a person’s height (for sleeping bags with a hood) or his height to the shoulders (for sleeping bags without a hood).
— The width at the shoulders is such that the sleeping bag fits tightly and at the same time does not interfere with movement.
— The width in the legs (for cocoons, see “Type”) is such that you can slightly bend your legs without tension on the fabric of the sleeping bag (otherwise heat loss is possible, and it will wear out more).

Note that these requirements apply primarily to sleeping bags intended for use in cold weather. If you are purchasing a sleeping bag for summer trips, the width requirements are not so critical - the main thing is that it does not feel cramped and the length matches.

Of course, when folded, the sleeping bag takes up significantly less space - see “Dimensions (folded)”.