Hi jstpeter. You'll need to qualify your question a bit to ensure you get the information you're looking for. In other words, what do you mean by really hot? Also, 'extended use' should be clarified by the types of applications that would be running during this period.
In my experience, when running a graphics intensive game like Witcher 3, I've observed the laptop does get warm around the battery area and the area where the motherboard is typically located. It doesn't get too warm that it's untouchable but contact with those parts of the unit is not comfortable. As an aside, the fan seems to be a bit noisy, which I think is a common callout with this laptop model. I don't have any information on CPU intensive applications so am not able to provide guidance here.
If one is just using the laptop for simple activities like perusing the internet, heat is not an issue.