After being in there for an hour, the thermometer reads 91.4F. It's fairly warm out today (weather.gov reports us at 34F), so the boiler isn't going full-tilt.
I haven't really worried about condensation because it's not only warm but also dry in there. My riding clothes dry out really really well in there.
The rubber and plastics is more what I had in mind when I asked the question, and the grease, whether the hot/cold cycles will negatively impact the bike.
So far it sounds like I should be ok.