You can do the following things --
1)Keep your laptop on a flat surface so that proper airflow is maintained.
2)Elevate your laptop: Keep a book below it
3)Buy a cooling pad
4)Keep your laptop in a cool environment (Air Conditioner )
If the above doesn't work, i would recommend you to call Dell support and state your issue to them. I guess they will replace the heat sink and cooling fans.
Thank you for your message. Does the system get hot only when gaming?
There are a lot of resources used while gaming & in-turn will emit a lot of heat. However, this shouldn’t be too uncomfortable to touch. Make sure that the air vents are clean & there is no dust accumulated.
As suggested by apandey287, use the system on a flat hard surface.
Run a hardware diagnostics by following this link http://bit.ly/2fJuGXB & check if there is an error.
What is the version of BIOS installed?
For my reference, please click on the message tab next to your avatar– click “New Message” & search for my Dell username (Dell-Sreejith R) & send a private message with the service tag, registered name & email address.