A thermal management system includes a housing having an interior space; a heat-generating component disposed within the interior space; and a working fluid comprising a halogenated material disposed within the interior space such that the heat-generating component contacts a liquid phase of the working fluid. The system further includes a bellows assembly disposed with the interior space, the bellows assembly comprising a first bellows and a second bellows. The first bellows is in fluid communication with the interior space and the second bellows is in fluid communication with an environment external to the housing. The first and second bellows are mechanically coupled such that expansion of the first bellows causes contraction of the second bellows, and contraction of the first bellows causes expansion of the second bellows.