An integrated thermoformable splint and heater and method for manufacturing same includes a thermoplastic material and an oxygen activated heater operatively associated with the thermoplastic material. The integrated thermoformable splint and heater are sealed within an oxygen impermeable housing. Oxygen is allowed to activate the heater either by removing the assembly from the sealed housing, or, by displacement of a removable seal that will allow oxygen to penetrate a porous region in the housing, and, in turn, come into contact with the heater.
