Why is the sun so damaging at altitude?
The risk of sun damage is actually greater in the snow because the thinner atmosphere is less effective at filtering out ultraviolet (UV) rays. Even though it may be cold, UV exposure is 5 percent greater for every 1000 metres above sea level. In addition, snow reflects between 50 – 90 percent of UV rays, which significantly increases your chances of getting sunburned on exposed areas such as your eyes, face, and underneath your chin. This is different to surfaces such as sand at the beach, which are more likely to absorb UV rays.
