It is the sub-category of infrared (IR) - near infrared (IRA) with wavelength of 740 to 1400 nm - that we should be concerned of as more than 65% of IRA reaches the dermis.
In fact, the IR component of solar radiation reaching the Earth's surface is mainly IRA. Another major source is the increased use of devices emitting artificially generated IRA radiation for therapeutic or wellness purposes.
IRA radiation has been demonstrated to alter the collagen equilibrium of the dermal extracellular matrix in at least two ways: destruction of collagen and reduction in collagen synthesis.
Despite similar biological effects to UV radiation, the underlying mechanisms are substantially different. Studies show that IRA induces ROS formation in mitochondria, which is the powerhouse of cells. The disturbance of the production of energy for biological process affects the proper functioning of our cells and tissues.
Sunscreens neither filter nor reflect IR radiations. Check out JAN's APA Complete for infrared protection.
Source: NCBI, Technology networks