Greetings, kelpie160!
Thanks for reaching out to the Apple Support Communities! It sounds like you're having concerns with the temperature and the battery life on your iPhone. For issues with the battery life, we suggest checking out this article for Batteries - Maximizing Performance. This article will give you tips you can try to optimize the settings on your device to get the best battery life. Once you've made the adjustments, use your iPhone normally for 24 hours and see if the battery is performing properly.
For the issue with the iPhone overheating, check out this article with more information about Keeping iPhone, iPad, and iPod touch within acceptable operating temperatures. This article will give you information about when you can expect your device to be warmer than normal.
Let us know the results and have a wonderful day!