Vacationing is one of the cons about owning chickens. You can also try to find a local 4H kid who loves chickens that might be willing to help out for free.
Hello, Connie, and welcome to BYC! :frow Glad you joined.
Leaving them locked in the coop in the TX heat for that long is an extremely bad idea. I would ask the helper to come twice a day to let them out and put them back in.