While they are both portable sleeping accommodations, camping sleeping bags are quite different from indoor sleeping bags. You'll want to sort out the differences before you invest in either kind.
Sleeping Bag Defined
All sleeping bags, whether intended for camping or indoor use, are basically bags that zip closed and are rolled up or stuffed into a sack for storage. A number of factors differentiate indoor from outdoor sleeping bags including the fabric material, filler material, size, shape and temperature rating.
Indoor Sleeping Bags
An indoor sleeping bag is generally much less expensive than a sleeping bag designed for camping or backpacking purposes. It generally will not provide the warmth and comfort of a sleeping bag designed for outdoor use. An indoor sleeping bag, often called slumber bags, are generally used for sleepovers by children. They may come in handy for younger members of the family when overnight guests means you have more people than beds. These bags often have cartoons or other popular media caricatures on them. Generally, they are not weatherproof and are not intended for outdoor use in cold weather conditions.
Outdoor sleeping bags, on the other hand, come in a variety of shapes, sizes, and with a variety of filling materials that make the bag not only comfortable, but lightweight and easier to carry.
What to Look for in Outdoor Sleeping Bag
When considering a purchase of an outdoor sleeping bag, some of the factors to consider are: type of insulation fill, temperature rating, and size.
Sleeping Bag Insulation
When considering a bag for camping or backpacking, the type of insulation is extremely important. The two basic options are down fill or synthetic fill. If you will be using the bag in a rainy, humid climate, you'll want to choose a synthetic fabric. Synthetic filled bags are easier to dry out if they become damp or wet. Down, on the other and, holds water and is difficult to dry out once it becomes wet. However, down is lightweight, is easier to carry, and is comfortable when used for sleeping in a dry climate.
Unfortunately, there is no universal temperature rating for sleeping bags, only the ratings provided by manufacturers. The temperature rating is designed to set standards for temperature ranges for comfortable sleeping. If you are choosing a bag for yourself or someone who prefers sleeping in colder temperatures, then you will want to choose a bag with a temperature rated for lower temperatures.
There is a wide variety of sleeping bag sizes that is designed for a greater user comfort. These include double sleeping bags for couples; mummy bags (designed for a tighter more secure fit – also warmer), and smaller sleeping bags for women and youth.