Choose the shape of your sleeping bag
This advantage: its slender and compact shape not only improves the thermal efficiency of the sleeping bag, but also saves luggage space, especially the head pocket can prevent a large amount of heat from being lost.
Disadvantages: Its relatively compact shape inevitably makes some people feel uncomfortable during sleep.
Advantages: On the basis that the temperature insulation effect is still good, it can provide a larger space for activities, thereby improving the comfort of sleep to a certain extent.
Disadvantages: Because there is more air to be heated, compared to the mummy-shaped sleeping bag, this kind of sleeping bag has a slightly lower thermal insulation effect. Moreover, since it is not designed to ensure the comfort of sleep, some people may still feel that this kind of sleeping bag is not spacious enough and comfortable.
Rectangle (rectangular) or envelope shape
Advantages: Its rectangular shape makes the space for activities during sleep larger, so it is more comfortable.
Disadvantages: Not only the thermal performance is average, but for most people, its volume and weight may appear too large.