There's something to that. Nevertheless, I never get nausea upon entering a building.

Well - most buildings.

Anogar, perhaps it would be helpful, in addition to watching your hydration, to allow your body to cool down to such a level that you feel cold again before you enter the building. I mean, cold. Not cold enough or long enough to get sick, but cold enough that you're feeling the environmental temperature as you normally would - which means your body temperature has fallen enough that when you enter the building, you're entering it on the same terms as everybody else.

If you want to do this, it takes a while. 10-15 minutes minimum, I would think.
I don't do this myself, although I do sometimes wait a few minutes (up to 5) before I enter my building.