Dontrelle Willis isn't Latino... and he grew up in the projects in Oakland, where it is decidedly un-hot, meaning he didn't have a lifetime of conditioning to the heat. Kenny Rogers seemed to figure out how to pitch well in Arlington.
If you throw strikes and keep the ball on the ground, you'll have quicker innings and, with them, more frequent trips to the dugout for water. Keep hydrated and the heat's not as big of a factor, especially for athletes that are supposed to be in top physical condition.