Living in McMurdo is really pretty comfortable, considering that you're in Antarctica: all the buildings are toasty and warm, and equipped with all mod cons. However, the weather is not so simple, and can change pretty quickly...
We went to condition 2 for a short period yesterday. Condition 3 is normal weather, with no restrictions on activities, although this can still encompass some pretty nasty weather. Condition 2 means that it's got really windy/cold/low visibility and you really don't want to be outside - certain activities are restricted, and work tends to stop. Condition 1 is a proper storm where you're not allowed outside. If this hits when we're at Byrd then emergency procedures kick in.
Anyway, condition 2 meant it was time to put on some extra layers and wrap up warm to scamper between buildings. However, it's so warm inside, that you have about a 2 minute window to get out before you completely overheat!!
I had the same trouble camping out the other day - I'd prepared for a proper cold night, and ended up roasting in my giant fluffy sleeping bag with its fleece liner!
It's all very tricky, and I haven't quite got the hang of it yet. I'm looking forward to getting to Byrd, where it is simply cold.