i am not worried about it because i don't like to be out in the sun and the heat so of course now neither does romeo! he is used to life inside in the cool air. if you let him outside and he feels it is too warm he does his little business and comes back to the door to be let in! he does not take off to go play at all and his little tongue is hanging and he is panting! if we are outside and comfortable and yet he feels it is too warm he goes and lays in my canna lilly's to play!
they are not that tall - maybe 18 inches - but tall enough that they provide him with the shade he needs when he wants it.