7 Try to Keep It out of Direct Sunlight

Even if it’s not a particularly warm day, direct sunlight can cause your iPhone to heat up past the safe threshold. If it gets too hot, you’ll usually get a safety notification on your device. Even you don’t, it’s still smart to keep it in a shady place and refrain from using it while it cools down.
You shouldn’t charge your iPhone when it’s in direct sunlight, either. Depending on the voltage of the charger, it can get dangerously hot. While first-party batteries have mechanisms to combat overheating, you can run into trouble if you’re using a non-genuine battery.