(Content / Images courtesy blueboltgear.com) A sleeping bag keeps you warm and provides a comfortable sleep (important for recovery) during the (very) cold nights at high altitudes. It basically traps the body heat using insulation material to keep you warm. There are two types - 1. mummy bags which fit tightly around your body and can feel a bit restrictive while sleeping. 2. quilts which are more spacious and open at the base (insulation is ineffective when compressed) where you sleep directly on your sleeping mat / pad.

A sleeping bag (especially those for sub-zero temperatures) is generally one of the heaviest and most bulky items in your backpack. It's therefore important (for those hiking regularly) to invest in a lightweight bag which usually has down or synthetic isolation material offering good warmth to weight ratio. Synthetic has the advantage to be more suitable for wet hiking environments.