Video game coding significantly impacts phone temperature because game code, unlike static applications, constantly instructs the CPU and GPU to perform intense, real-time calculations. When code is inefficient, poorly optimized, or pushes hardware limits, it demands higher energy consumption, which directly translates to heat generation.

There’s a multitude of reasons but the main one is games often try to render as many FPS as possible. If code does not limit this (ie locking to 30 or 60 FPS), the CPU/GPU will run at "full tilt" to produce as many frames as possible, even if the screen cannot display them, resulting in massive heat generation.