Duv hates the way Barrayarans forget that they breathe. It's only ever a conscious act for them when some deliberate action deprives them of oxygen.
Like being strangled.
Barrayarans think controlled environments are the province of travel into dangerous environments: space, the ocean, the past. But spaceships and sea ships and the climate-controlled documents rooms are rare. For Barrayarans, controlled rooms signal something vast and unconscious, an instinctive fear. Duv's watched scholars and recruits alike choke on recycled air and struggle to get back their breath, to learn to breathe again.
It's another stark reminder: this is not his home.