I suppose that’s not really typical.
I’ve been using FW12 on my lap even when gaming and watching some videos, it’s totally “OK”. Watching videos and light gaming (like visual novels), causal browsing lead to at most 60 degrees after some settling down from booting up the system.
If you’re using FW12 in tablet mode, it might heat up a bit more, from what I’ve heard.
I suppose that the target temperature is somewhere about 60 degrees, by default, because:
That’s what my thermals look like after I started a few web-services in containers, and then left them running (as well as writing this comment, and all the other apps I have opened, the system is a bit busy, I’d say)
The spike is obvious, but then the cooling system kicked in, and brought it down to 60, where it now rests, that’s on charger in normal performance mode.
While on my laps, the fan does spin, but it’s hardly noticeable, and the warmth that I feel through my pants is such that it feels somewhat pleasant this autumn day.
Resources reports 58 C on CPU while framework tool reports 48, so I’m not sure what’s going on here 
I’d suggest to take a look under the lid, and see if there’s something blocking air passage, if the fans constantly run at like 5000 RPM (or more), if it’s about 3000, that might be “OK”, however not under no load at all 