EDIT : I used a voltmeter and it's ok. There is 3.3v delivered. But the ESP is still hot. But maybe it's normal. My wifi key is 'hottest' than the ESP. Maybe he should heats a 'little' ?
And I make another measure. On the VCC (ESP) and the GND (ESP) there is about' 3.22V.
I think, this is normal, isn't it ?