I'm not sure if it has to do with the hot weather where I live but my Oreos always come apart neatly when I hold one side in each hand and twist each side in an opposite direction.
I think the key is to have a soft filling in the Oreo. By the way, it's always 32 degree Celsius where I'm currently living.
I usually have the opposite problem with Oreos, I have to keep them in fridge because I like them better cold.
