I only ever go to hot foriegn countries, so thats something I hate as I strongly dislike Summer and heat.
I hate the fact that planes are so heavy air conditioned. A few years ago, we arrived in Majorca on the hottest day ever recorded, got off the plane and the heat just hits you xD I almost fainted. Huge contrast from leaving Liverpool grey clouded and raining to that.
The language doesn't bother me much, as more or less everybody speaks some English, and there are English bars etc everywhere.
My parents always get non-air conditioned apartments too, so I sleep on the balcony usually, and get eaten by Mosquitos :{