Loft is a term generally used to specify what aspect of sleeping bags?

Loft refers to the volume or thickness of a sleeping bag when it is fully expanded. This measurement is crucial because it indicates the bag's ability to trap air and provide insulation. A higher loft suggests better insulation properties, as it can create a larger air pocket, which is essential for retaining body heat in cooler conditions. Therefore, understanding loft is key for selecting a sleeping bag that will maintain warmth in various temperatures.

While durability, temperature rating, and water resistance are important factors to consider when choosing a sleeping bag, they are not related to the specific term "loft." Durability speaks to how well the material withstands wear and tear, temperature rating indicates the lowest temperature at which the sleeping bag will keep an individual warm, and water resistance refers to how effectively the fabric repels moisture. Loft, however, is distinct and specifically tied to the bag's insulating properties.