Sleeping Bag Basics
Regardless of the style of sleeping bag you choose to use, the manufacturing process needs to also be considered. The smaller and closer the stitches are to each other, the better the bag. The stitches mean the bag will last longer, be more durable and you won't have to deal with ripping seams. Also, metal zippers are always more sturdy than plastic. A sleeping bag made of down is great if you can guarantee it won't get wet. Once wet, down will take forever to dry. Synthetic is more durable and the wisest choice, no matter the weather conditions it will be encountering. Choose a sleeping bag that has a rating ten degrees colder than you plan on experiencing.
These are the most commonly found sleeping bags and have been around for a long time. These bags are great for sleeping in warm conditions, but are virtually useless in the cold. Their bulkiness would make them a burden for backpackers. Rectangle sleeping bags are roomy and generally are pretty thick. You're also able to zip two together, so you'll be able to sleep double.
Mummy Bag Style
Mummy bags are less bulky and weigh less than a rectangular sleeping bag. There is also a semi-mummy bag, which is a bit roomier than the mummy style itself. The mummy bag conforms to the body, giving little to no space to move about. This utilizes and saves your body heat, keeping you warmer. Mummy bags of both styles also have a hood attached to the bag. The style of bags come in a variety of ratings and are good for using in cold weather. If you don't like being confined in tight spaces, a mummy bag might not be the bag for you.
Alternative Sleeping Bag Styles
There's a style of sleeping bag called the "half bag." These bags take up little space and don't weigh much, making them easy to transport for backpacking. They basically cover the lower half of your body, leaving your upper half uncovered. It's up to you to keep your upper portion of your body warm. The downfall in using a half bag is, you're unprotected from wet conditions or sudden cold snaps.
Hikers who will be carrying a sleeping bag for long distances should purchase the lightest sleeping bag that will meet their needs. Casual campers should purchase the sleeping bag that they find most comfortable.
When warmth is a consideration, construction is of the utmost importance. Look at the seams to evaluate stitching. Tight stitching will let in less air. Drawstrings will allow the sleeping bag to be cinched tightly closed to prevent air from entering. Built-in hoods on mummy sleeping bags, keep the head warm and help prevent the loss of body heat.
Sleeping bags come with a temperature rating to let the purchaser know what temperatures the sleeping bag is suitable for. Most people do not know that the temperature ratings are not always accurate. Temperature ratings should only be used as a guide and not the sole deciding factor towards the purchase of a sleeping bag. It is best to look at the construction and materials of a sleeping bag to determine the temperature rating.