Concrete and stone takes longer to heat up than wood. Of course the walls need to be thick, like 18 inches and the exterior finish has to be light colored. The same trip to the Caribbean where I stayed in the concrete villa, I went into a wooden building - a school house. It was hotter inside than it was outside and it had tons of open windows. The villa had large covered 'porches' ( for lack of a better term) around the whole structure, so sunlight never blasted into the interior of the house. Those galleries surrounding southern plantations served the same purpose. Additionally, humidity and wood are not mutually compatible. It's a good recipe for mold growth.