Hello maan144,
Thanks for asking the Apple Support Communities for help with your iPad heating up. We're happy to check this out with you.
First, please check this article: Keeping iPhone, iPad, and iPod touch within acceptable operating temperatures - Apple Support
"Your device might get warm
When you use the device or charge the battery, the device might get warm. You might notice that your device feels warmer in these situations:
- When you set up your device the first time
- When you restore from a backup
- When apps reindex or reanalyze data, like Photos tagging for faces, places, or keywords after a software update
- When you use graphics-intensive or augmented-reality apps or features"
As long as the device isn't showing the temperature warning or causing you pain or discomfort, this may be normal. If you are feeling pain or discomfort, I recommend you stop using the device and have the hardware checked at an Apple Authorized Service Provider or Apple Store for your safety.
Please review this help article prior to bringing your device in to be checked: Get your iPhone, iPad, or iPod touch ready for service - Apple Support
You can find a service provider using this link: Apple Find Locations
Thanks and have a wonderful day.