About one-third of us experience a yearly sunburn. Most people may believe that summer is the only time sunburns happen, but that's not true. Sunburns frequently occur during outdoor winter activities such as skiing, snowshoeing and sledding. You can burn even on a cloudy fall day.
The sun's rays, or solar radiation, spans wavelengths from 270 to 800 nanometers. White light — or visible light — that we see is between 400 and 800 nanometers. Ultraviolet B (UVB), with a wavelength between 290 and 320 nm, is mainly responsible for sunburn (think "B" for burn). When the shorter-wavelength UVB light is absorbed by skin, it causes damage that shows up as redness.
The skin is exposed to greater amounts of UVB radiation at higher altitudes and at midday, and closer to the Earth's equator.
Today's options for effective protection from sun damage are numerous. Choosing a combination of at least two modes provides the best protection. Lighter skin has less melanin from sunlight than does darker skin; therefore, lighter individuals must be especially meticulous and consistent in using sun protection, but individuals with any skin type should protect their skin from the sun.
Self-tanning preparations darken the skin by staining it, and while this method of acquiring a tan is preferable to UV light exposure, the tan from these products provides little or no protection. Therefore, other methods of sun protection must be used. These options include:
Sun avoidance when possible: Midday (10 a.m. to 2 p.m.) exposure to sunlight, when UV rays are most intense, should be avoided or minimized. If your shadow is shorter than you are, the damaging rays of the sun are at their strongest and you are likely to sunburn.
Sun-protective clothing: Long-sleeved shirts and pants made from a tightly woven, lightweight fabric are excellent adjuncts to topical sunscreens, activity permitting. The fabric should be fast-drying, because wet clothing is more transparent to UV rays than dry clothing. A wide-brimmed hat with a minimum of a three-inch brim adds extra protection for the nose, ears, throat and neck.
Sunglasses: These protect the eyes from UV damage that can result in cataract formation. A quality pair of UVA-screening and UVB-screening sunglasses, preferably in a wraparound style, should be worn outdoors in all daylight hours, activity permitting. Glasses that are merely darkly tinted, but do not screen UVA and UVB rays, should be avoided.
Chemical sunscreens: A broad-spectrum sunscreen with a sun protective factor (SPF) of at least 15 should be worn every day year round, even on cloudy days, to prevent cumulative skin damage from UV rays. To be most effective, these sunscreens should be applied at least one hour before sun exposure to be adequately absorbed into the skin. Sunscreens should be reapplied every two hours during activity, especially after swimming. A waterproof/sweatproof sunscreen with an SPF of 30 to 45 is best for outdoor sporting activities.
Physical sunscreens: These protect the skin by scattering UV light. These products typically contain zinc oxide or micronized titanium dioxide. Physical sunscreens are effective immediately when applied, since no absorption is necessary. However, they must be reapplied during activity and after swimming. The SPF guidelines mentioned above apply for physical sunscreens also.
If sunburn occurs, the discomfort, swelling and blistering may be reduced with some simple measures. Cool tap water compresses applied over an over-the-counter cortisone cream for one hour three times a day for the first 24 to 48 hours is soothing and helps stop inflammation. Oral antihistamines and oral anti-inflammatory agents (e.g., ibuprofen, aspirin) can also help counteract the swelling.
Alton Thygerson, professor of health sciences at Brigham Young University, is the National Safety Council's first aid and CPR author and technical consultant. For more information, the National Safety Council First Aid Handbook by Thygerson is available in local bookstores.