In choosing a sleeping bag for our expedition or our excursion, we must take into account some factors that will be decisive for our comfort and protection during the night hours.
First of all, we have to choose the shape of our bag, between the squares and the ones called "mummy", that are integrals allowing only the face out. The first category is more suitable for outdoor trips and light excursions, especially during the summer months. The second is definitely more technical, and although the bags of this type can also be used for excursions and trips, their use is more specific for the winter months and for expeditions at high altitude.
The second aspect to take into account when choosing a sleeping bag is the padding. There are two types of padding, in feather and goose down and in synthetic material. In the first case, we have maximum lightness and warmth, known characteristics of the feather; however, one aspect to consider is that this kind of padding is slower to dry and this aspect, in adverse weather conditions, can be a negative point. The filling in synthetic material, especially in recent years, has achieved excellent lightness and thermal insulation standards, keeping intact the ability to dry quickly, to allow a very technical use.
Another indicator to pay attention to is the weight of the sleeping bag, which increases in the case of sleeping bags designed for winter use. Between 125 and 175 grams we have a summer or half-season sack, up to 300 grams a lot for all seasons, plus 300 a winter sleeping bag.
One last aspect to consider is the strength of the nylon used in the external construction: the more resistant the material used, the more technical the use of the sleeping bag is, to deal with the eight thousand in safety and comfort.