Why is fibre a good at reducing heat loss in a sleeping bag?

Fibre is effective at reducing heat loss in a sleeping bag due to its ability to trap air within its structure, creating an insulating layer that retains body heat. The small air pockets within the fibre help slow down the transfer of heat away from the body, minimizing heat loss through conduction and convection. Additionally, synthetic fibres often have moisture-wicking properties, which can keep the sleeping environment drier and more comfortable. This combination of insulation and moisture management makes fibre an Excellent choice for maintaining warmth in a sleeping bag.