Esp 8266 getting hot

hello, it is normal for esp to get hot even if i don't send any data ? i've implemented espnow to communicate between 2 board but even if i don't send anything , the metal case gets a bit hot in minutes after powering from 10Ah phone battery pack .
is there a minimum distance that i need to keep between modules?

What's the voltage of the battery pack?
How is it connected, can you draw a quick diagram?

it is a regular 5v 2A 10Ah phone external battery pack and i power the board through the usb cable. after a few hours with no data sent it is still warm but i can touch it maybe above 30 C

I assume you mean the NodeMCU from your other thread(s).
It's better to ask these things in a single project thread, not open another thread.

The ESP8266 module (metal part) could get a bit warm (not hot) during normal operation.
Because it consumes 3.3volt x 0.1Amp = 1/3 of a watt.