Temperature rating is a very important factor. Unfortunately, there is no real universal system of notation for waist bags. Every manufacturer has a different classification system. The better the insulation, and attic of the building is what will determine how your waist bag. The higher the rating of the waist bag will be hot.
These estimates should also be the carpet in her purse. If you plan to use your waist bag in a variety of weather conditions (hot and cold), and then look at the waist bag of three seasons that the rate of 20 degrees. It is important to have a waist bag that provides insulation and fiber quality up. This loft in the waist bag and more loft it means that they will keep warm.
Differential cut waist bag, wherein the coating is less than the shell for maximum thickness. Waist bags are often filled or goose or duck, but can also be filled with insulation. Completed between the shells of the waist bag, and then blocked. Down waist bags are usually lighter and more compressible. If you want to travel light, and you are camping in a dry place is best suited for you.
If it gets wet, it may take a while to dry, so keep it dry. Synthetic fills less than down, but better quality synthetic not far from losing quality. If you need a waist bag that can handle wet or humid, then you are best man. Unfortunately, weigh more and take up more space. There are also all kinds of shapes and sizes.