for red apples, the skin is usually soft enough to be edible, but the green ones on the other hand sometimes have hard skin, so its not always the case for the green ones to have their skins edible(but there might be some of those with soft skin though). I'm pretty sure all red apple skins are edible though, if you want to be safe then just wash it.
but I would prefer the red ones though(although I rarely eat apples myself as I prefer oranges) cos they are sweeter, green ones tend to be a bit more sourish.
and no they don't cool you down as much as watermelon does as they are not so juicy, but what they have is more fibres and vitamins I think.
Last edited by Bolter; 07-21-2010 at 02:11 AM.