Hello Alhopper21,
If you're noticing any heat from your iPhone we recommend starting with the guidance listed here: If your iPhone, iPad, or iPod touch gets too hot or too cold
This article shares some examples of why your device might get warm. Regarding message delivery, if you experience an error review the steps listed here: If you can't send or receive messages on your iPhone, iPad, or iPod touch
"If you see a red exclamation point
- If you try to send a message and you see Exclamation mark icon with an alert that says Not Delivered, follow these steps:
- Check your network connection.
- Tap Exclamation mark icon, then tap Try Again.
- If you still can’t send the message, tap Exclamation mark icon, then tap Send as Text Message. Messaging rates may apply. Contact your carrier for more information."
Best regards.