How come my phone restarted?

[Alain_A]

When I was out and about.
I have the L625 with 8.1 on it. I use bluetooth headset when I go out. The phone was in my top shirt pocket which is loosed. An hour later my headset tells me " out of range."
Took the phone out of my pocket and sure enough the WP logo was on with the phone being very warm to touch. It's a good thing that I have a thick shirt otherwise I would have burn my nipple.
That would have been very ugly with a burned scare.

So anyway, anyone encounter this?

 

[kingenu]

mt ativ s, restarted once today, wasn't warm though

 

[Alain_A]

I guess it is not happening to too many peeps

 

[Ashalinia]

This happened to my 1020 once after the 8.1 update and I was surprised since I've never encountered it in the past (except on my old 521.) Wasn't hot though.