Respiratory infection of over-reaction?

[engywook]

Hi all,

I'm concerned that dear Polly may have the beginnings of a respiratory infection. Given that getting her to a vet would involve a 1.5 hour train ride and a decent amount of stress for her, I thought I'd check here before doing that. (The logisitics aren't normally that complicated, but I'm at a research station at the moment, so...)

She was wrapped around my neck and sitting on my head last night; my ear was against her side and it seemed to me like I could hear a sighing sound when she breathed. My girlfriend, who was in the same room, didn't hear anything. Shortly afterwards, Polly hissed, which was clearly audible. I didn't hear any pops and there's no discharge from her mouth or nostrils. She was in a bit of a bad mood, so is it possible that what I heard was simply heavy breathing? However, she did spend one night at 98% humidity about a week ago*, so I'm a bit concerned as a result. Even though I should leave her alone (she's in a new box), I'll take her out tonight and listen again. Is anything else I can check for? Am I over-reacting?

* (I wanted to move her & Monty into new (plastic!) boxes....I had them set up and everything was fine, but I didn't take into account the possibility that she would knock over the water bowl, which soaked everything and sent the humidity straight up. I've since fixed the boxes and buttressed the water bowl, so everything should be fine now. They moved in properly last night.)

Thanks.

edit: I forgot to mention that she's been behaving normally -- she's her usual active, somewhat shy, curious, friendly self and doesn't seem at all unhealthy. The final point is that she's going into shed (she's just gone pink)...normally, I would bump the humidity to 70-75%, but if she's facing an RI, is that wise?