[iMore Question]

My phone was outside, partly in sun, on 97 degree day recently and the "too hot for use" warning came on. Phone was taken inside and allowed to cool off to room temp over a couple of hours. Now the display will vary from normal to fading to stripes of green and purple, but the message/app or whatever is open will still be somewhat visible. I do not know how long it was exposed to the sun/heat, but probably more than an hour before i noticed it.

[Rob Phillips]

Welcome to iMore! How long have you had it back inside? Electronics are incredibly sensitive to heat. Hopefully there isn't permanent damage but there's no promise. Reset your device by holding the power button and home button down simultaneously until you see the Apple boot logo and see what happens once it's back up and running.

[nikkisharif]

Heat can definitely cause damage to devices. You might want to take it to Apple so they can check it out.

[SwitchBeach]

LCD = LIQUID Crystal Display https://en.wikipedia.org/wiki/Liquid-crystal_display

They are sensitive to heat for sure.