I am not banded yet but I live in Mississippi, so it's very Hot and Humid and I'm sure it was change in climate. We use to have a ranch in Darby, MT and while the summers got hot...there was NO humidity compared to what I normally lived in and I LOVED IT! I would think it would be similar to me coming there and having altitude sickness. It always took me a day or two to settle in once we got there. I think it's just what our bodies are use to. So sorry you it sick for the first of your trip.