On Windows there is an odd way of throttling which only sometimes triggers and lowers CPU frequency to 1380 MHz. It is bypassable via custom power plan. As I said, it only sometimes triggers. On Linux iGPU is never throttled and CPU is throttled around 97 C to speeds slightly below max MHz. Shutting down is, under normal circumstances, for situations where throttling fails. I have another laptop which successfully throttles and keeps temps below 90C.