Abstract: An insole includes a top wall and a bottom wall constructed from an air-impervious material. The top and bottom walls are heat-sealed at a durable side wall ridge to form an envelope having a heel, intermediate and front zones. A porous pad is contained within the envelope. Vent openings are provided only at the intermediate and front zones for ingress and egress of air from the envelope as the wearer walks on the insole. The total area of the vent openings in the front zone is greater than the total area of vent openings in the intermediate zone, thereby facilitating movement of air throughout the insole without imparting excessive pressure at the side wall ridge.