I’m planning on buying a laptop for making games when i’m on the way (I already own a desktop one) and i was thinking of the new Dell XPS 15 (i7-8750H, 1050 Ti, 16gigs RAM, 1080 display) but i’ve heard that it has some thermal issues at gaming and maybe it can affecto also UE 4 development .
So what do you think will it have any problems? The reason I’ve chosen this one because of it’s building quality / price.
All laptops have issues with getting overheated
I hear Dell XPS are not good for content creation. They are more like high powered laptops for general use.
Look up reviews on laptops to get an understanding before committing to buying anything.
https://www.youtube.com/results?search_query=dell+xps+review
Airflow is always important for laptops. but I game and dev on mine regularly. Most have weak GPUs to save battery use. This XPS only has a 1050Ti. I would try for something higher powered. GTX1060/1070 if you can stretch to that. (I have a 980M, with a battery life like an egg-timer. 
).
For laptops, make sure you put them on a hard, flat surface, so air can get underneath it to cool the innards. If you put it on a bed, for example, it will overheat horrifically.