Reduce the game settings -- this just is not a gaming system of any caliber.  That will reduce the temperatures.

I always play games at low-medium settings only. I prefer performance and cool temperatures than graphics.

Also, I play games which are like 5-10 years old, not any new ones.

Btw, this increase has happened after a latest BIOS update.

Your Dell computer can overheat because of insufficient air flow due to dust or debris blocking the air vents, exhaust ports, or a clogged fan. An overheating computer can intermittently restart, shutdown, or experience performance issues. Eventually excessive heat can damage the internal components.

I am using a laptop stand since January to ensure airflow