We all know tanning can cause skin ageing and skin cancer. Although it is important to avoid excessive UV radiation, sunlight positively affects the body’s resilience, and synthesis of vitamin D. Sunlight also boosts our mood by raising endorphin levels. Pay attention to how much you spend in the sun and protect yourself. Three types of UV radiation are classified according to their wavelength: UVA, UVB, and UVC. The ozone layer protects us from UVC radiation. Medium-wavelength UVB is filtered by the atmosphere – although a small percentage does reach the Earth’s surface. Long-wave UVA radiation is not absorbed by the ozone layer. UVA radiation intensity does not depend on the season or time of day; UVA can penetrate windows. UVB rays are most intense at midday and closer to the equator, where the path through the ozone layer is the shortest. That is why maintaining the ozone layer is so important.