CHOOSING A SLEEPING BAG
Selecting the right sleeping bag is one of the most important requirements to good camping. A lot rides on getting a good night's sleep in the outdoors - fitness levels, safety, and of course, sheer appreciation of the scenery, the invigorating air and the terrain.
types of sleeping bags are available internationally, the choice in India
is rather restricted. What kind of bag is best for you will depend on several
factors : the climate, temperature and altitude where you will be using it;
what you like to have next to your skin, and whether you will be carrying
it on your back or in a vehicle.
An important adjunct to your sleeping bag is a sleeping mat or ground mat, which is placed on the ground under the sleeping bag. Usually made of some kind of lightweight foam, the sleeping mat provides insulation and cushioning against the chill and unevenness of the ground.
Basic Sleeping Bag Shapes
are basically available in two shapes, rectangular and mummy-shaped.
What would be best for you will depend on where you intend using the bag and how you like to sleep.
A rectangular sleeping bag is just that - a rectangular sleeve into which you climb. It ends abruptly just above the shoulders, leaving your head and neck open. A mummy bag has a hood which can be pulled around your head, exposing only your face.
The advantage of a rectangular bag is that in most models, two of them can be zipped together to form a double bag, for two people. In the case of mummy bags, you need to have one left zipper and one right zipper - and the feet remain separated as the zipper does not extend all the way around the toe of the bag.
If you are the kind who sleeps with arms and legs all sprawled out, then the rectangular bag might be better for you. However, if you like to sleep curled up and snug, then the mummy-shaped bag is your answer.
Many backpackers also prefer the mummy-shaped bag as its tapered shape and hood serves to keep out the chill. The shape also reduces its weight by several hundred grams, a factor that is a critical when you are backpacking over long distances, and every gram matters. As the mummy bag is smaller with less spare air space after you get in, it requires less energy to heat up at night than the roomier rectangular sleeping bag.
General size options include junior, regular and extra-long. Extra-wide sizes are also available. The longer sleeping bags are often preferred for winter camping as backpackers store extra gear (boots, torches, batteries, drinking water) at the foot of the bag to keep it warm and dry for the night.
Additional factors that should be kept in mind when you select your sleeping bag are : your body's metabolic rate during sleep, expected levels of fatigue, calorific intake prior to rest and the type and quality of the tent you will be using.
Like all quilts and covers used to cover oneself while sleeping, sleeping bags also work on the same principal of not allowing body heat to dissipate. The temperature rating of a sleeping bag will depend on its construction and the type of material used.
The rating normally refers to the lowest temperature at which a user can be comfortable in a sleeping bag. This rating should however be used only as a guide -it would be best if you used this keeping in mind your bio-rhythm when sleeping.
No known study has been conducted in India on the temperature rating of bags. International standards also vary between manufacturers: basically the weight and type of filling used gives a certain amount of insulation, this is largely used as a thumb rule to indicate a temperature rating for a bag. The construction and method of seam sealing are also factors that affect the insulation provided by a bag.
All international temperature ratings are based on the assumption that a sleeping bag, when used outdoors, will be used with a sleeping mat under it.
The ideal bag for round-the-year use with sleeping mat, in India, for moderate climates, would be one rated about 5 C/ 40 F internationally.
Kinds of Insulation
Sleeping bags come with a wide variety of insulation options. What you select will depend on your usage and mode of carriage - with lighter, more compact ones being the preferred option for backpacking.
Internationally, the best choice for regular travel is a goose-down filled bag, which is extremely good for dry weather conditions. More convenient for back packing and sleeping on uneven ground would be a synthetic fibre filled bag, which also dries out fast if it gets wet. A variety of synthetic fibres are used, the best among these being the hollow fibre.
However, goose down bags are not available in India, and good quality hollow fibre filled bags are hard to find. Very good cotton filled bags are available, but they do not last long, do not dry easily and get lumpy.
The best lining for sleeping bags will be a waterproof material that does not add to the weight and size of the bag, and is easy to maintain. Nylon taffeta is the most popular choice.
On the trail, it is extremely important to keep your sleeping bag dry. The best way to do this is to always carry a large plastic bag (the Ziplock variety if you can) in your backpack. If you expect rain, stuff your sleeping bag into the plastic bag for extra protection.
Your sleeping bag should always be aired after a trip and fluffed up before being put away. Store it in a dry place away from damp and mildew.