I think you might be overthinking a little bit too much, unless you plan to keep your iPhone more than 3-4 years.
It is not going to stress with temperature enough to accelerate life of battery or component enough to have effect within 3-4 years.
I keep my iPhone 2 years most, it is probably not something I have to worry about for the iPhones I own.
I am a product test engineer, dealing with 2-corners, 4-corners test daily. If you understand what I said you will understand what I mean.
It is not going to stress with temperature enough to accelerate life of battery or component enough to have effect within 3-4 years.
I keep my iPhone 2 years most, it is probably not something I have to worry about for the iPhones I own.
I am a product test engineer, dealing with 2-corners, 4-corners test daily. If you understand what I said you will understand what I mean.