If you spend any time swimming the waters of agua azul, bring lotion if you burn easily. With the water so cold, the burn sneaks up on you.
Bring lots of water wherever you are in Palenque...it is a HOT town!
Miscellaneous: I would definitely bring bug repellant if you spend any time in the jungle. Melissa and I camped unexpectedly in the jungle for a night. I had on layers and layers to keep out the rain, cold and bugs. The bites that showed up days later (I never felt a thing) are still visible a month later!!!!
Luggage and bags:
do not take with you a lot of luggage. it can be difficult to carry out everything.
Clothing/Shoes/Weather Gear: Use cotton wear and do not forget your sunglasses and an umbrella. It is very hot and wet there.
Toiletries and Medical Supplies: Malaria can be a problem. So, be careful. Take your mosquito repellent and do not drink water from everywhere.
Photo Equipment: take your camera with you. this is more important than your mosquito repellent.
As you can see from the picture, there is a light haze here. It's jungle country, so expect the humidity and hot sun! Light clothing here is a must! Shorts and a t-shirt is what I wore, and I was still hot!! Some good walking shoes are also recommended as you can lose your footing easily on the rocks and stairs.
Toiletries and Medical Supplies: I didn't have a problem with mosquitos, but you may want to bring some repellant if you like. I didn't have a problem with sunburn either.