The most critical issue in choosing a mountain equipment sleeping bag is to choose a suitable temperature scale according to the use environment and your own cold resistance. Standard mountain equipment sleeping bags generally indicate the scope of application of sleeping bags with four different temperature indexes, of which four temperature scales respectively indicate:
Comfortable temperature: Indicate the maximum temperature that the sleeping bag can be used under. At this temperature, you will not be as hot as a sauna.
Target temperature: indicates the upper limit of the design temperature of the mountain equipment sleeping bag. At this temperature, you will feel more comfortable, but this temperature refers to the difference of 10 degrees Fahrenheit from person to person.
Extreme temperature: indicates the lower limit of the design temperature of the sleeping bag. At this temperature, you may feel uncomfortable, but wearing warm clothes can safely enter the sleeping bag.
DANGEROUS TEMPERATURE: The use of this sleeping bag at this temperature may pose a threat to your health, and it is compulsory to use it. Wear all warm clothing when using it.