Comparison Terra Incognita Siesta 400 Regular vs Terra Incognita Alaska 450

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).

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.

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.

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.

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)”.

The height of the person for whom the sleeping bag is designed. For more information on choosing the correct size of a sleeping bag, see the paragraph "Length".

The dimensions of the sleeping bag when folded, when packed in a complete cover; if this cover is made in the form of a compression bag(see "Equipment"), then the dimensions are indicated with the compression straps tightened to the maximum.

Other things being equal, the smaller the size of the sleeping bag, the more convenient it is in storage and transportation. At the same time, more compact models are usually more expensive.