At high altitudes, the sun's rays are more intense due to the thinner atmosphere, which provides less filtration of ultraviolet (UV) radiation. This increased exposure can lead to a higher risk of sunburn and long-term skin damage. The intensity of UV radiation increases by approximately 10% for every 1,000 meters (3,280 feet) of elevation. Understanding the heightened risks associated with sun exposure at high altitudes is crucial for anyone planning outdoor activities in mountainous regions.