I'm surprised the average is only 3 stars for this place. It's not the fanciest nail spa in scottsdale, but the women in there are incredibly sweet, very efficient (without being rushed) and they do an excellent job and the cost is reasonable.
I've never been there during the Summer, so I can't comment about the interior temperature control.
Overall, a great place to go for your regular mani/pedi's. I usually get a regular pedicure and a gel manicure and it costs about $48. It's a little more for the french manicure, probably around $7 extra. Well worth it.