Keep Your iPhone in the Right Environment
As you may know by now, high temperatures can damage your iPhone. Something as normal as the summer heat can be dangerous for your iPhone if you don’t protect it.
Charging your iPhone in high temperatures can ruin the battery faster too. Not only will you need to let it cool down before you can use it, but it can be permanently damaged if your iPhone gets hot too often.
Keep it between 0º and 35º C (32º to 95º F) and avoid leaving your iPhone in the car or open spaces where the sun can hit it for too long.