Screen & home button too hot to even touch, after water damage?

Hi, a few weeks ago my iPhone 6s went to sleep, along with me, in the tub. I did the rice thing, didnt work. Took some pieces in the phone apart to let them dry, mostly covers, shields, etc. got. I’ve left the phone apart for a few weeks, just to make sure it was dry.

I put a new battery in, & put the phone back together, except for closing the case. I hit the home button but nothing happened. I let it sit for a minute, then picked it back up, only to have my finger burned by the screen & home button. Nothing came on the screen.

I immediately unhooked the battery from the phone. But the actual back of the phone was cool? I hadn’t ever taken the other half of the phone, the screen side, apart because it appeared to be sealed & I was afraid to mess with it. I still haven’t.

After the burn incident, I looked Where the back of the home button is, & noticed there was a small piece of adhesive from the edge, near the backside of the home button, & going up behind the home button & disappearing. I used a tool & easily pulled it out.

Could that have possibly caused the phone to get so hot? Or, did I maybe just short circuit it when it went for a swim, & killed it? Please help me, can’t afford a new phone at the moment. Back to my old 5s, which I’m fed up with, but thankful I have it. thank you in advance for your help!! :)