Hello Lowe1974,
There can be numerous causes for an iPhone feeling warmer than normal. Numerous factors can influence the temperature of the iPhone, including:
* Setting up your device the first time
* Restore from a backup
* Wirelessly charge your device
* Use graphics-intensive or processor-intensive apps, games, or features, including augmented-reality apps
* Stream high-quality video
Other factors and steps to take can be found at If your iPhone, iPad, or iPod touch gets too hot or too cold - Apple Support. After reviewing that article, let us know if you have further questions.
Thanks for using Apple Support Communities!