I've had a nightmare this weekend! Sitting in the garden on Friday afternoon, and went inside to take a call on landline and left my iPhone outside in the sun. Can and back half an hour later and the thing feels like it's just came out the oven!
Temp warning on screen, so bring it inside to cool for an hour. Upon restart, top half of screen is completely unresponsive to touch, bottom half fine.
Managed to do a restore through iTunes, and a DFU restore but no dice. Spoke to Apple, nothing they could do apart from suggesting sending it to them for repair (£300).
So new phone arrived today from John Lewis, and I'll deal with the repair when Apple Store is back open.
I saw this on their website, so hoping I can get a free repair as it falls in line with the description of the fault:
iPhone X Display Module Replacement Program for Touch Issues
support.apple.com