what do i do when S6 switches off by itself

[AC Question]

The phone just switched off and the Samsung logo is flashing slightly it is also hot.

 

[belodion]

If extensive heavy use beforehand did not cause it, take it to a repairer for diagnosis.

 

[B. Diddy]

Welcome to Android Central! Let it cool off for a few minutes, then charge it on a wall outlet for at least 4-6 hours (and make sure it isn't getting hot while charging). Now try powering on again. Does it work?