Abstract: An ankle brace product including an ankle brace for being custom-formed to the shape of an ankle while flexible and upon hardening providing a rigid, supporting custom fit. The ankle brace product includes an outer container formed of moisture-impervious material and a flexible ankle brace positioned in the container in substantially moisture-free conditions and sealed therein against entry of moisture until use. The ankle brace includes an elongate substrate with a reactive system impregnated into or coated onto the substrate. The system remains stable when maintained in substantially moisture-free conditions and hardens upon exposure to moisture to form a rigid, self supporting structure. An elongate, flexible protective pad is positioned on one side of the substrate along its length to provide a cushioning barrier between the substrate and the skin of a patient when the ankle brace is in use. An outer wrapping encloses the substrate and the protective pad.