Firebase Messaging in Unity : Device is going to hot

Question

this is my situation.

• using Unity.

• using firebase messaging SDK for unity.

• using the android phone.

• using google play service in my project.

I installed the latest version of firebase messaging SDK to my unity project.

it works well, has no problem.

but Firebase messaging SDK makes my phone so hot.

I think this SDK is using many CPU resources.

it's not happened before installing firebase SDK to my project.

if I turn off the app or go to background, it's cooling down so fast.

I don't want to make a heater app with firebase OMG!

help me plz...