How are you measuring temp?
What's your ambient temp?
Are you using mobile data or WiFi for watching reels when you observed that temp?
On a relatively hot day, 35C, while using mobile data, even my S20FE 5G would cross 40C battery temp. Else, I think it is usually around 5C higher than ambient normally on WiFi. Now in a 21C AC room, a few mins of insta on data causes battery temp to go upto 29C.
I am using battery guru app to measure temp, I have also tried Gsam battery monitor.
I got identical results.
I am using WiFi, atm there is no SIM in it. (I wonder how the results would be after I insert a SIM card and use data)
I have another 2 year old phone, Vivo Y91i (older & cheaper)
I used it in the same room, connected to same wifi and watched an hour of insta reels, the temp reached 36C and was stable.
whereas the poco m4 pro 4g display initself feels really hot, also the glass part in the rear, whenever I switch to the old phone I feel its much cooler.
This phenomenon is normal and is simply due to the device's CPU activity. When running multiple apps, the CPU processes more tasks and as a result, additional heat is given off. This happens on most electronic devices (even computers/laptops), including the devices of other manufacturers.