s6 overheated and cut off now won't cut back on

[Sword hawk]

So my Samsung s6 phone said it was overheated and would cut off until cool down but now will no longer cut back on

 

[B. Diddy]

Welcome to Android Central! The battery might have failed. Charge it on a wall outlet for at least 6 hours undisturbed, then press and hold Power for 20 seconds. If nothing happens, bring it to a repair shop, since the battery probably needs to be replaced.