I bought a new Inspiron series 3000 15 3567 2 weeks ago (on 18/11/2017).
Official Dell web page link: 
My issue here is, on 19/11/2017 I downloaded League of Legends, a not very demanding game.
First game, laptop goes on sleeping mode after 20 minutes. End game, laptop goes to sleep mode again, and that was like 10 minutes after first shut down.
Issue has been present every time I try to play.
I know it is not an overheating issue, because the laptop is never on my lap, nor on a cloth, or a flat surface, I have it ALWAYS on a cooling unit (heavy duty, 3 fans). Also. it is BRAND NEW.
Today (29/11/2017) Dell Tech Support told me:
1.- Inspiron 3567 Core i7, 8GB RAM, AMD Radeon R5 M430 2GB, is a "basic" laptop, and it won't let me play more than 20 minutes (all this via dell chat).
2.- Inspiron 3567 Core i7.... is not able to run ANY games, as it is not "designed" for playing, and I should buy the Gaming series for ANY game. Also, that my GPU was fried/damaged because I tried to play. They "confirmed" that laptop is just for videos, word, powepoint, and that's it. (Via call to Tech Support).
I need help from the REAL PROS here. I think it might be an issue with the BIOS thinking 20°C is OVERHEAT.
Ohm and another thing, I switched from a REAL basic laptop: Acer Aspire E1 (Core i5 5th Gen, Intel HD Graphics 128MB, 4GB Ram) that I bought 3 YEARS AGO, and it never overheated even after 6-7 hours of playing.