Comparison Naturehike M400 vs Terra Incognita Asleep 400

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.

The highest ambient temperature at which a person can comfortably spend the night in a sleeping bag without excessive sweating and overheating of the body. The parameter is indicated for conditions when the hood and zipper of the sleeping bag remain open, and the hands of the sleeper are outside the sleeping bag.

The comfort limit temperature of this sleeping bag.

Some manufacturers use their own criteria for specifying this temperature, but EN13537 is considered the generally accepted standard. According to him, t of the comfort limit is the lowest ambient temperature at which a man in thermal underwear can comfortably sleep in a sleeping bag all night (at least 8 hours) in a heat-saving position (curling up) without waking up from the cold. Such criteria are used taking into account the fact that men are less likely to get cold during sleep than women, and the acceptable temperature for them is slightly lower. Of course, in each individual case, comfort will also depend on the characteristics of the body and the preparation of the tourist. However, in general, the general rule is: if the sleeping bag is used by a man, then the minimum temperature at the place of lodging should ideally be between comfort t and comfort limit t; for a woman, a few degrees must be added to the comfort limit t, and it is best to focus on comfort t (see above).

This indicator is quite closely related to seasonality. So, for winter use, t of the comfort limit should be less than -4 ... 0 °C ; in the warmest models, it can be very low, -15 °C and below. In purely summer and even spring/autumn models, there are values of +10 °C and even higher, however, if you are afraid of sudden col...d snaps at night, it is advisable to choose sleeping bags with indicators of at least +6..10 °С, and preferably +1...5 °C(especially for the off-season).

Some manufacturers use their own criteria to indicate this temperature, but the generally accepted standard is EN13537. According to it, the comfort limit t is the lowest ambient temperature at which a man in thermal underwear can comfortably sleep in a sleeping bag all night (at least 8 hours) without waking up from the cold in a heat-saving position (curled up). Of course, in each individual case, comfort will also depend on the characteristics of the body and the training of the tourist.

The comfort temperature of this sleeping bag.

Some manufacturers use their own criteria for specifying this temperature, but EN13537 is considered the generally accepted standard. According to this standard, comfort t is the lowest ambient temperature at which a woman in thermal underwear can comfortably sleep in a sleeping bag all night (at least 8 hours) in a relaxed position without waking up from the cold. This definition is taken from the considerations that women are more likely to get cold during sleep than men. Of course, the actual comfort will depend on the characteristics of the body and the preparation of a particular person. However, most likely, at ambient temperatures at the level of comfort t and above, it will be comfortable (or even hot) in a sleeping bag for any user, regardless of gender. For details on temperature selection features, see "comfort limit t" below.

Specific values of t comfort in modern sleeping bags can often be -5 ..-9 °C, or even lower, however, there are also models for hot weather — + 10 ... 15 °C and even higher. At the same time, we note that seasonality and the possibility of winter use are not strictly related to this indicator: in particular, winter models can have a comfort t of +15 °С, or even +20 °С.

Some manufacturers use their own criteria to indicate this temperature, but the generally accepted standard is EN13537. According to it, the comfort limit t is the lowest ambient temperature at which a woman in thermal underwear can sleep in a sleeping bag all night (at least 8 hours) in a heat-saving position (curled up), maintaining thermal balance. Of course, in each individual case, comfort will also depend on the characteristics of the body and the preparation of the tourist.

Extreme temperature of this sleeping bag.

Some manufacturers use their own criteria for specifying this temperature, but EN13537 is considered the generally accepted standard. According to him, the extreme temperature is the temperature at which a well-trained female tourist of a dense physique (height 160 cm, weight 60 kg) in thermal underwear can spend the night (at least 6 hours) in a sleeping bag in a heat-saving position (“kalachik”) without the risk of hypothermia. Such criteria are taken from the considerations that a person's resistance to cold depends on gender (women are colder than men), physique (thin people are more sensitive to cold) and training. It is worth noting here that if you are not used to hiking conditions, then the extreme temperature should be considered as the lowest temperature at which you can spend the night in a sleeping bag without risking your life. At the same time, there is no question of comfort, in addition, there is a high probability of hypothermia; so at such temperatures, not only high-quality thermal underwear, but also additional insulation may be required.

— 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.

The number of individual layers of insulation provided in the sleeping bag. The multi-layer construction significantly improves the "warming" characteristics of the sleeping bag — firstly, due to additional layers of air between the layers of the filler, and secondly, by overlapping the seam of one layer with another layer. For summer sleeping bags (see "Seasonality"), 1-2 layers are considered sufficient, in autumn-spring they are usually 2-3, and in winter — at least 3 layers.

It is worth noting that the number of layers is usually indicated for a synthetic filler (see "Insulation"); down insulation does not fit in layers.