When I decided to have the deck I built 25 years ago, I decided to go for the composite material base (over pressure-treated woof posts and joists). At the same time, I was sufficiently worried about a HUGE oak tree hanging over the house that was starting to drop large branches. So the tree went (saved a dozen 6' long 4" branches to use to smoking meat on the offset smoker).
But 2 things happened. First, the removal of the huge oak tree let a lot more afternoon sunlight onto the deck, which I thought a "good thing". Second, I discovered that the composite deck base heats up a lot more than plain wood does.
The cats alerted me to the heating problem. They ran out on the new deck when the oak tree was removed and ran back into the house. I put my hand on the deck and took it right off fast! It's HOT! My kitchen temperature probe said it reached 115F! That was not something I expected OR was warned about.
Temporarily, I have put outdoor carpet runners (by name and literally) in some paths that get the cats safely to the stairs out to the yard and to shaded spots on the deck. I am looking into awnings (openable/closable like Sunsetter and possibly permanent ones) that will keep the deck cool.
The heat on the deck isn't constant. It is shaded about noon to 5 pm. But a couple hours before Noon and after 5pm, it get seriously hot. Even I have to put a towel on the top rails so that I can stand there leaning on them.