Abstract: A boot or shoe 10 has its upper lasted to an insole 12 made from leather or a permeable plastics material, and a sole unit 13 is bonded to the lasted upper and the insole. The sole unit is moulded from a resilient plastics material and is formed with a multiplicity of cavities 15 opening to its top surface underlying the insole and open topped channels extending between the cavities. Bulges 17 are formed on the bottom surface of the sole unit at the locations of the cavities. The act of walking causes the bulges to be compressed and to pump air along the channels to others of the cavities so as to disperse perspiration from the insole. The cavities preferably have a restricted cross-sectional area 18 where they communicate with the channels.