I live in Norway with CO's, but I have also lived in the West Indies (Barbados, St. Vincent & The Grenadines) with dogs. I had pits and mix breeds with long and short coat. From my experience the dogs in the West Indies would find a shaded spot in the garden, dig into a little cool dirt and make themself comfortable while enjoying the breeze from the Passat trade winds. Now I lived on a hill sourrounded by rainforest, wich actually kept it quite cool, also during daytime. But if you live in open areas, or places with little or no breeze it could be a very different temperature.
My point, I would have no problems keeping CO's in the area I lived in Vermont (Penniston Valley), St. Vincent, while most places in Barbados would make the dogs suffer from the heat. So really where and how you live in the Caribbean does make a difference.
Compared to the Caribbean, Norway does not have summers, only two winters, one green, and one white :D