A lightweight, thin-walled heat resistant plastic container containing hot-filled liquid contents, comprising: a spout for filling the container with liquid contents; a closure configured to seal the spout; a base including a bottom portion that is bent toward the spout, the base including a structural reinforcement configured to withstand hydrostatic pressure from the hot-filling of liquid and configured to prevent significant deformation in the base upon the cooling of the hot liquid; and a sidewall extending upwardly from the base toward the spout, the sidewall including a zone of deformation, wherein the zone of deformation in the sidewall is configured to accommodate an initial deformation due to the cooling of the contents and to substantially regain its initial shape upon the relieving of immobilized stresses.