Described is a self-sealing thermal enclosure. In various embodiments, the self-sealing thermal enclosure includes an enclosure having a wall with an opening. The enclosure is configured to surround a temperature-controlled environment. The self-sealing thermal enclosure also includes a porous seal disposed adjacent to the wall at the opening. The porous seal is compressible and is fabricated from an open cell foam material. When the porous seal has absorbed a fluid such as a condensate, the temperature-controlled environment is sealed from an ambient environment such that the flow of air into or out of the enclosure is substantially reduced or eliminated.