After the onset of the Melding Plague various individuals sought to remain implanted with nanotechnologies, for either quality-of-life or life-extension reasons. To that end, the wealthy could purchase Palanquins. Hermetically-sealed, mobile environments, they allowed their users to travel in plague ridden areas without fear of infection.
While used by the upper echelons of post-plague Chasm City society, they also served as a means for habitat dwellers to come and go from the surface without exposing themselves or their clean orbiting environments to any risk of infection.
The users/inhabitants of palanquins were referred to as "hermetics".