How protect oneself from sunburn?
The intensity of the sun differs around the world by the following: Latitude (hotter nearer the equator); Altitude (even though it may be getting colder the higher you go the sun is getting stronger); Season; Time of day; Reflection (water, concrete, snow etc)
When one is exposed to any artificial source of UV, special protection should be worn. To protect himself or herself from the natural UV of the sun, one should wear long sleeves and wide-brimmed hats or use an umbrella. It is also recommended to avoid prolonged outdoor activities during peak hours of UV exposure -- approximately from 10 a.m. to 3 p.m., if possible. Commercial preparations are available that block UV. These sunblocks have a sun protection factor (SPF) rating. Dermatologists suggest that one should buy sunscreen that has an SPF of 15 or more and that one follow the directions regarding how often to reapply carefully.
Most people benefit from sunscreens with sun protection factor (SPF) numbers of 15 or more. The SPF number gives you some idea of how long you can stay in the sun without burning. For example, if you burn in 10 minutes without sunscreen and you apply a liberal dose with a SPF number of 15, you should be protected from sunburn for 150 minutes. Sunscreens with SPF numbers higher than 15 may work better for people who are fair-skinned, live at high altitudes, work or play outdoors much of the day, or perspire heavily. Swimming and perspiration reduce the actual SPF value of many sunscreens - even those that are water-resistant - so you have to reapply the product often.
Sun-protective clothing offers another way to protect skin from the harmful effects of the sun. Sun-protective fabrics differ from typical summer fabrics in several ways: they typically have a tighter weave or knit and are usually darker in color. Sun-protective clothes have a label listing the garment's Ultraviolet Protection Factor (UPF) value, that is, the level of protection the garment provides from the sun's ultraviolet (UV) rays. The higher the UPF, the higher the protection from the sun's UV rays.
Experts estimate that a significant percentage of our exposure to sun occurs by age 18. That's why it's especially important to apply sunscreens with a minimum SPF of 15 to children's skin about 30 minutes before they go outdoors. Reapply sunscreens after they swim, towel off or play hard. Talk with teachers, child care providers and camp counselors about scheduling outdoor activities to reduce children's exposure to the midday sun, when the sun's rays are most harmful.