With increasing amount of heat dissipation, smartphone manufacturers are starting to implement cooling systems inside the smartphones. The first and currently the only Samsung smartphone to feature some kind of cooling system was the Galaxy S7 series.
The phones pack a small heat pipe that is only 0.4mm thick. It cools the chipset and brings the heat to a graphite sheet on the back where it is dispersed. For the new Galaxy S8, Samsung was experimenting with the two-pipe design, but decided to stick with the tried and tested design.