The answer is: Infrared Rays (IR) and Ultraviolet Rays (UV).
The sunlight that impacts human skin is composed of 7% ultraviolet radiation, 39% visible light and 54% infrared emissions. Therefore, we are exposed to a greater load of IR rays, the difference is notorious. 65% of infrared radiation is called infrared A (IR-A) and penetrates our skin to a depth of 10 millimeters. This means that it reaches the deepest layer of the skin, the hypodermis, and alters its DNA. It is a dry heat that does not increase the surface temperature of the skin, so we are not aware of the damage it causes.
Curiously less talked, we have the infrared rays, which are the cause of that sensation of heat and well-being produced by the sun’s rays on the body. But at the same time, these are responsible for sunstroke and heat stroke. This is especially dangerous in the case of babies and children, since their thermoregulation system has not yet fully developed and is very sensitive. Also adolescents, the elderly and athletes are at risk groups. In addition, infrared rays also influence skin aging.
On the other hand, as humans our intention must be to find a balance, because we should not pretend to live without sun, the ultraviolet radiation coming from the sun is necessary for many of our biological processes, for example the human being uses it to synthesize vitamin D, but in excess ultraviolet radiation is very harmful.
According to Doctors from the Skin Cancer Foundation, the use of protective creams is insufficient and indicate that the use of hats can be as or more effective than the application of sunscreens, especially to avoid burns to the skin of scalp, face, neck and shoulders.