Do what all of the other posters have said

I went in February 2004 with my then almost 3 yr old dd and my 7 mos old dd. My 7 mos came down with RSV while we were there. Of course, she had been sick with a cold two weeks before that and was more likely more apt to be vulnerable to it. She was VERY sick and so lethargic and we were a bit scared being so far from home. She ended up at the hospital and had a vapour treatment and x-rays done. She didn't end up being admitted thankfully. She was healthy by the day we were flying home

Poor kid. I was still nursing her, so I think that did help her somewhat. She reverted to wanting to nurse frequently, so needless to say mommy didn't get a lot of sleep on this trip!
We went again with the kids in March of this year and again the same dd became sick. This time she had the Norwalk Virus (the lovely vomitting and diarrhea bug). It started our third day there and didn't end until the day before we left. It was great fun

. Thankfully the older dd didn't get it at all. She had a great trip (my parents were along so we had extra hands to help keep her entertained).
I worry that she will be the kind of kid that will get sick every time we travel. So many people tell me about the "air on the airplane" being at the root of it ... and I do wonder ... but am not entirely sure this is the reason. I am just praying that she doesn't get sick on our next trip. She has missed out on so much fun
Oh ... and we did have both of the girls get their flu shots. I felt that at least this way they had a better chance of not coming down with it. You can do a flu shot by 6 mos, so you may want to consider this being that you are going during the time that flu season begins.
Have fun ... and don't worry too much ... it may end up being totally fine for you or it could be something like an ear infection or cold, which you just can't prevent! Just be prepared for anything
Kerri
p.s. I teach school too ... what grade do you teach? I teach kindergarten!