you might consider taking your phone to the nearest Authorised service center since you have done all kinds of homemade remedies and I'm not sure this is a hazardous range of temperature for the phone.
Unfortunately most of the authorized samsung service centres in Chennai are not responding for calls and if they respond, they notify that they can't assist before June 1st. Its very uncomfortable to use the phone as the temp is too high near the Bixby button
temperature raise bcs of following reason : 1. surrounding temperature 2. heavy app running in background 3.battery strain due to overcharging or draining to 0 % 4.taking video for a long time 5.new update issue
Regarding the listed items 1. Tried using at night when the temperature is very less compared to day time, the issue persists 2. verified App issue history and nothing is listed. also tried Optimization option and closed all background apps. Issue persists 3. Charging upto 90% and not 100%. also tried turning off the phone while charging still the phone heats up for a while. 4. Using camera for 1minute shoots up the temp from 34°C to 39° or above. 5. I'm not sure if that's the trigger. I'm clueless as I've tried all the options. It's also disappointing that no Samsung authorized Service centre within a radius of 10km from my place is responding. Being helpless **bleep** 😐
yaya bcs of corona issue everyone aware but its not good .. r u facing the issue from start?.. normally battery will go from 34 up to 40 its common but you feel the warmth .. I never faced the issue before after the new patch there is heating issue ,slow charging issue most of the users facing this issue.