Overexposure to ultraviolet radiation over many years causes serious health problems such as skin cancer. Clothing that is sensibly designed for sun protection reduces your exposure. Materials with Ultraviolet Protection Factor (UPF) ratings of 40 and higher provide all-day protection for the fairest skin. A garment only protects the skin it covers. Protect your head and exposed skin by wearing a hat. Sunglasses and sunscreen and use shaded outdoor areas.