They don't want you to burn your testicles when keeping it in your lap.
https://download.lenovo.com/pccbbs/pubs/x1e_p1_gen5/html/htm...
> The Cool and Quiet on lap feature helps cool down your computer when it becomes hot. Any extended contact with your body, even through clothing, could cause discomfort. If you prefer using your computer on the lap, it is recommended that you enable the Cool and Quiet on lap feature in UEFI BIOS:
(it can be disabled on this laptop)
more: https://askubuntu.com/questions/1416567/disable-lap-mode-on-...