Look for sunscreens labeled "broad-spectrum," as these provide protection from both UVA (aging) and UVB (burning) radiation. Both UV and visible light can induce skin cancer.
SPF (Sun Protection Factor) denotes the effectiveness of a sunscreen against UVB rays. A minimum SPF of 30 is prescribed for most individuals.
Reapplication of sunscreen is required every two hours or immediately after swimming, perspiring, or towel-drying.
Most individuals do not apply sufficient sunscreen. For full-body coverage, dermatologists recommend using approximately one ounce (a shot glass full) per application.
Although water-resistant sunscreens adhere better to damp or perspiring skin, they are not completely waterproof.
As up to 80% of UV rays can permeate clouds, it is essential to wear sunscreen even on cloudy days.
Exposure to UV radiation increases by approximately 4% for every 1,000-foot increase in altitude. In high-altitude regions, additional solar protection is required.
Any prolonged exposure to the sun, such as city walking, hiking, or even transportation, requires the application of sunscreen to exposed skin.
Certain medications, such as certain antibiotics and acne treatments, can increase your skin's sensitivity to the sun, making the use of sunscreen even more important.
Children have more sensitive skin than adults, so search for sunscreens designed for children and consult a pediatrician for infants under six months.
If you have sensitive skin, you should perform a patch test on a small area before administering a new sunscreen to larger areas of your body.