The Snapdragon 815 is coming this year, We have heard a lot of things about hot Snapdragon 810 chipset and its alleged overheating issues. We still don't know the whole outcome of the story as there are almost no real tests that show if the Snapdragon 810 processor really suffers from overheating.
However, there are several reports, especially the recent HTC One M9 overheating issues, that showed high operating temperatures. The issues seems to be fixed with the upcoming Snapdragon 815, which runs at 100.4 degrees (38° C), compared to the 107.6 (42° C) degrees by the Snapdragon 801, 111.2 (44° C) degrees by the Snapdragon 810. Since there isno real test of the Snapdragon 810, and the Snapdragon 815 is still far away from production.