Avoiding Intense Overexposure to Sunlight Staying out of the Sun. Reflective surfaces, such as water, sand, concrete, and white-painted areas should be avoided. Clouds and haze are not protective, and in some cases may intensify UVB rays. Ultraviolet intensity depends on the angle of the sun, not heat or brightness. This index is valid for about a 30-mile radius around the city from which the broadcast originates.
Higher altitudes appear to reduce the time it takes to burn.
Sun lamps and tanning beds provide mostly UVA rays, and some experts believe that 15 to 30 minutes at a tanning salon are as dangerous as a day spent in the sun. Sunscreen s and Sunblocks. Sunscreens and sunblocks, used generously, may help prevent skin aging and many skin cancers. Studies are conflicted, however, over whether sunscreens provide protection against melanoma, and some even question their value against more common skin cancers. The bottom line is not that people should avoid sunscreens but that they should always use them in combination with other sun-protective measures.