Apple invented infrared reflective paint that doesn't heat the iPhone in sunlight.

I don't know if you've found that if you use your iPhone in the sun or in other infrared environments, its screen and body will heat up. This is because the device absorbs thermal radiation. Even with infrared reflections or absorption layers and

coatings, these absorbent layers or coatings generally have a color, so they form a specific color, and have an opaque effect. These coatings or absorption layers should be used on electronic devices, and their overall appearance may change as a result.these shaded layers do not emit light and heat radiation well, and sometimes even absorb heat from infrared light, so the above-mentioned heat conditions occur.
to solve this problem, Apple is also actively looking for solutions. The U.S. Patent and Trademark Office recently released a patent obtained by Apple that describes the new infrared reflective layer that Apple invented. With this layer of reflection, the device will not be severely heated even if it is exposed to direct sunlight.
also described in the patent documents the use of coatings on components of electronic devices that use infrared reflectors. According to Apple's approach, a set of polymerization structures is suspended in a liquid, each of which has a well-defined inner and outer diameter. Apply the liquid containing these polymer structures to the component, the liquid evaporates, and the surface of the component forms an infrared reflective layer or coating.
Apple said in patent filings that the technology could be used on screens, casings, glass-covered or other parts of electronic devices such as iPhones, iPads and MacBooks.