The ability of insulation and comfort in a sleeping bag temperature depend on three fundamental characteristics:
1. Quality of the raw materials used in their manufacture.
2. Structure or design of the SAC.
3. Size and metabolism of the person using it.
1. Quality of the raw materials
• Of all the raw materials, the most important is filling, better to be one who is able to retain more heat.
• There are stuffed with down and polyester fibre. The first, if it is high percentage of down (90% down, 10% Feather) and high weight, has a higher calorific yield but low life expectancy; While polyester fiber has a low maintenance and long life.
3. Size of the user
• The complexion of the person change a sack in a substantial way comfort temperature.
• The human body is a generator of heat at a constant temperature of 36 ° ± 1 °.
• A petite person will occupy less volume inside the SAC and therefore there will be a greater volume of air to be heated.
•A person of medium/large size will occupy a larger volume within the SAC and therefore not be an excessive volume of air this will achieve greater temperature.
• A person of very large build will stop small volume of air to heat for what will not get not heat it until it has escaped abroad.
2. Structure and design
As the bag is structured according to the profile standard of persons (Mummy type), the SAC isolate better and if it has side walls evenly distributed the hot air around the user. See details on Pima official site.
The hot air inside the bag due to the temperature of the human body will leak abroad being renewed by more dense than the previous cold air.
Structure of the SAC and the size of the person will condition the speed of warming and leakage in a continuous process of convection.
Maximum is the highest temperature where a partially uncovered build STANDARD man has no sense of excessive heat and therefore no sweats.
Comfort is the lowest temperature in which a woman build STANDARD and a man of what a complexion, relax on your back position has no feeling of cold.
Limit is the lowest temperature that a shrunken build STANDARD position man has no feeling of cold
Extreme is the lowest temperature at which a woman
build STANDARD and a complexion man
MENUDA, it runs the risk of HYPOTHERMIA.
According to its own build user-selectable sleeping bag that it requires paying attention to temperatures that certifies the manufacturer under testing in government laboratories.