How about getting it braided?
I usually wear mine pulled back and up in a scrunchie or band of some kind. There is probably not a picture of me anywhere with my hair down and looking good when it's hot/humid.
Another pony tail or other hair-pulled-back style advocate.
If you use styling products, they melt and run and get all sticky and yucky. You probably could use a bit of leave-in conditioner, but even that can be uncomfortable by the end of a long, hot humid day.
First time we went to Disney, I was INTENT on looking good for the camera, so the first morning I woke up...flat ironed my hair and sprayed some sort of Dehumidifying hair spray in it...
We headed over to MK and onto Splash Mountain...long story short...got splashed with one of the water cannons....hair destroyed...flattened to my head, dripping down my face and into my eyes....hair spray in my eyes and my contacts....our photo looked a sight.
Never again. Pony tail.