Sleeping Bag

A Sleeping Bag (sleeping bag) is a bag used for sleeping. The vast majority of sleeping bags on the market are labelled with a comfort temperature and an extreme temperature. The comfort temperature is the range of temperatures at which the user sleeps throughout the night, with a maximum and a minimum. The maximum comfort temperature is the kind of heat you feel in a sleeping bag but not when you are sweating profusely, and is generally defined as a sleeping bag with the zip open, arms outside and the head of the bag not tightened, etc.

Development history
Early humans were using animal fur to make warm clothing and sleeping mats, which are still used today, including by the Eskimos living near the Arctic. early 19th century explorers and mountaineers began to test different sleeping bag systems, early sleeping bags were filled with camel hair, which has excellent insulation properties, and then a hollow rubber air mattress was invented and used in the 18th century In 1861 Francis Fox Tuckett tested the first Alpine sleeping bag prototype, and in the mid-1860s the envelope sleeping blanket design began to be perfected, and near the ground are hollow rubber coating as a ground thermal insulation layer.

The role of the sleeping bag is simply to keep heat loss to a minimum, while the body inside the sleeping bag is constantly generating heat to keep warm, the amount of heat generated varies from individual to individual and from situation to situation, all sleeping bag temperature calibration systems are based on a standard human body, but such a standard human body basically does not exist. A sleeping body has approximately 75-100 watts of thermal power, which translates into approximately 47-55 watts per square metre based on the surface area of the body. The amount of energy produced by metabolism is very complex and relates to age, gender and even the amount of fat under the body, but by and large a fit young male always produces far more body heat than an older man or woman. The perception of cold is related to age and experience, with novices generally feeling colder than experienced climbers. People who work outdoors a lot feel warmer in cold conditions than those who work in an office a lot.

Use
Whether it is a down or synthetic cotton sleeping bag, try not to compress it up when it is not in use for a long period of time to keep it as fluffy as possible, and it is good to get a proper tan. The purpose of this is to maintain the nature of down and cotton and extend the life of the bag, especially for down sleeping bags, try to keep them in a special down sleeping bag storage bag (loose breathable cotton bag). As a personal hygiene product, try to avoid borrowing each other's sleeping bags.
When using a sleeping bag there are several ways to improve warmth.
Equip a good quality moisture-proof pad, which is very important, as anyone who camps a lot has experienced, if the cold air goes straight from the ground to the back, that kind of cold is unbearable; drink a hot drink before bed if possible, milk and fruit jelly are fine to warm up the body.
Eat a comfortable meal before bedtime, especially with carbohydrates (starches, sugars).
wearing a long set of thermal underwear and clean socks will be very effective.
wearing more clothes when the sleeping bag is not warm enough, or covering the sleeping bag with clothes and other items.
sharing a tent with a larger number of people.
lighting a gas lamp or cooker in the tent if it is safe to do so.
Build a fire. There are so many ways to do this, so try them out when it matters.