If the pool area is predominantly in the sun most of the day, the patio will be very hot and uncomfortable.

We go through this with many clients when considering a bluestone patio.

We install a lot of Indiana Limestone as it is cool in the sun. The colors in the stone work well with colors and textures used around a pool.

Essentially any dark materials, even some pavers, can become very hot.

We had bluestone coping and stepping on it when it had been in the sun was VERY uncomfortable. Super hot. I would not use it again, and most definitely not for a deck.