In my company we use iPads as display screens for other equipment, this requires it to be in an easy to view position which means on the dash and subsequently means they get a lot of heat from the sun causing the warning message to display, easy fix is just to stick a sun reflector on the top of it to stop direct sunlight and no heating issues whatsoever.
My personal tablet is an Android and attaches to my kneepad, when in direct sunlight it gets extremely warm, I've have it refuse to recharge once and subsequently have been more conscious about using our aircrafts Sun Visors to keep the direct sunlight off it and have since had no problems at all.