iPhone 15 pro overheating

I've been using Iphone X for 6 years and it's broken so have to get a new one. I bought Iphone 15 Pro 256gb on January 23rd 2024. My phone heated up like crazy on first charge. The next week it got so warm even when I scrolled on Facebook for 30 minutes, or talking on the phone for 45 minutes. It gets so warm when I simply switch between apps like Facebook, Instagram, whatsapp, youtube at the same time for only 15 mins. When I put my phone in the pocket, it's so warm that my skin is irritated even though there is a layer of fabric in between. Very disappointed with this product.

I talked to Apple staff and they told me to upgrade to Ios 17.3. Did not fix a thing.

Getting warm or even hot during setup would be expected and normal. The battery is working very hard as data is loaded on it. It is NOT overheating unless you see a message saying the phone needs to cool down.