Abstract: An improved sports boot is provided for use by snow skiers and the like, wherein the boot includes an improved boot liner interposed between a substantially rigid outer boot shell and the foot and lower leg region of a skier. The boot liner is defined by flexible sheet material extending about selected anatomical zones of the skier's foot and lower leg region to define a plurality of relatively small chambers each of relatively low vertical dimension and partially filled with a metered quantity of substantially uniform sized particulate. The boot liner further includes a plurality of small vents for restricted air passage between adjacent chambers, with one of said chambers communicating with a main air discharge tube.