Why is my phone say over heating

@hikmaayel first of you need to establish if your phone is indeed overheating. If it is not, then the issue could be with a few of the thermistors. There are some on the battery, so you do want to go ahead and replace that first. A bad battery can cause this. After that you, will need to check the thermistor on the charging board, (I would replace the daughter board) as well as on the logic board. The location for the thermistors on the logic board is a bit tough to find, since there are multiple variants of that board. So we would need to know your phones exact model number. Something like SM-A105(whatever letter)

Here are the locations for the A105-F/M and G variant

The listing for the thermistors is

THERMISTOR NTC SAMSUNG 100KOHM,4250K,1MWC,TP,0.6

Samsung part number 1404-001724

This guide will show you hot to replace the battery and the charging board Samsung Galaxy A10 Charging Port Replacement