Compared to most phone case materials leather is an insulator
Compared to most phone case materials leather is a good heat insulator. So something that would have fit in the thermal envelope of another phone, may be too hot for this use case.
Qualcomm is hitting back at the suggestion its Snapdragon 810 system-on-chip overheats, while carefully making sure it doesn't call its customer LG a cheapskate. Critics argue that if the 64-bit ARM-compatible Snapdragon 810 was problem-free, it would have been chosen by LG for the new flagship G4, which was launched this week …
8-core, DDR4 memory, and 64-128 GB of SSD... These things are boasting more resources than my 3-year-old luggable workstation. Seems that phones are going with the model "don't bother optimizing code because the hardware will make up for it" that has been plaguing desktops for the past few years.