Battery Low [Q] When does a hot battery become a problem?

Hello XDA peeps,

I currently have an LG G2 for a week now, one of many android phones that have been tweaked and improved thanks to XDA expertise.

I have used my phone as an hotspot recently (I often do in all my phones) and left it over night to download something. As expected, it was quite hot when I woke up this morning so I closed the internet to let it cool down.

Then it hit me - will exposing the battery at such heat lead to irreversible effects down the road? Should I be concerned in this one instance?