Sorry for the long delay. Things have been... hectic at work and home the last few days.
So, people seemed torn between a simple breathing mask and a full helmet setup. Personally, I lean towards the breathing mask and goggles, with a heavy coat to keep warm out in the intense cold of the aether.
But nobody (granted, out of only 22 responses) believed you could survive - at least for long - unprotected in the aether, nor did most anyone opt for a full-fledged 'aethersuit.'
Now, as always, in My Victorian Universe, the required equipment is waht I say it is. Which is breathing mask, eye protection, and a coat (at least for anything more than a very brief exposure).
So my masked minions are kitted out for aether service as well as anonymous feats of anarchy and terror. So I just got to get them painted. I figure that will be sometime this summer, maybe June-ish?
[Added Note: I think of a breathing mask as just covering the lower face, providing air, but not eye protection. Goggles would be needed to protect eyes.]