Why is my phone showing me over heating

@calmanleonard of course, first you need to rule out if it is really overheating. If it is, then we will have to deal with that first. Should it only report that it is overheating, but it is not feeling hot etc. it is possible an issue with the multiple thermal sensors on your phone. The very first one I'd replace is the battery and second the charging board. After that, re-evaluate to see if the message stopped from showing up.

Since iFixit does not yet have a guide for this, use something like this video to work on it. Replacement batteries and charging boards are readily available at many online stores.

While you work on your phone, take lots of pictures. Once you are done with it, take those pictures and create a guide for iFixit. That will help the next person that has the same problem as you do. It's easy and fun to create these guides. https://ifixit.com/Guide/new The iFixit community will appreciate this.

Repair is War on Entropy!