I am near Dallas so I well understand how a person would suffer without AC in their vehicle. I was recently in Cartagena, Columbia which is as hot and humid as Hong Kong or Bangkok...absolute sauna. Before we went, I made *scarves* for the two of us and put those water absorbing crystals in them:

They absolutely saved us. We were the only people with them in the tour group, but the rest were falling by the wayside and couldn't keep up...even those younger than us. They absorb so much water that it took them eight days to fully dry out again. My scarves had four *pockets* and I put about a 1/4 teaspoon of the crystals in each pocket and thought it wouldn't be enough but it was almost too much.

While I love the idea of this homemade AC unit, when you are out and about, these things can be lifesavers.