It may take a day before you see the full rosy damage. Pop aspirin immediately? It may lessen early development of sunburn. Drink water. Treat first- and second-degree burns with cool baths, moisturizers such as aloe vera and hydrocortisone creams. See your doctor if burns accompany headache, chills, or fever.
Wrong. Exposure to UV rays can mutate your cells and cause cancer. Blistering sunburns during childhood and adolescence increases your risk of developing <A HREF="http://www.livescience.com/humanbiology/060513_skin_cancer.html" class="nexthead">skin cancer</a> as an adult, because <A HREF="http://www.livescience.com/humanbiology/060207_melanoma_detection.html" class="nexthead">melanoma</a> has more time to develop over your lifetime. Other nasty effects: wrinkled and leathery skin, brown sunspots, and cataracts.
The sun's rays can reflect off of sand and water (snow, too). And there are other factors: UV is strongest in the summertime, at midday, at higher altitudes, and close to the equator. Even on a gray day, up to 80 percent of the sun's rays can pass through <A HREF="http://www.livescience.com/php/multimedia/imagegallery/igviewer.php?imgid=190&gid=15&index=0" class="nexthead">clouds</a>, mist, and <A HREF="http://www.livescience.com/forcesofnature/041104_fog_types.html" class="nexthead">fog</a>.
Not quite. SPF tells you how long you have before you burn. Wearing SPF 2 lets you stay in the sun twice as long as without. An SPF 30 gives you 30 times your natural protection, and deflects 97 percent of the sun's burning rays, whereas SPF 15 deflects 93 percent.
The most effective <A HREF="http://www.livescience.com/imageoftheday/siod_051129.html" class="nexthead">sunscreens</a> protect against both UVA and UVB rays. They work by either chemically absorbing UV rays or deflecting and bouncing them off your body.
Melanin helps the body filter out UV radiation, but it also can be harmful. Pheomelanin, the type of melanin that makes red and blonde hair and fair skin, actually increases the risk for sun damage, such as sunburn and <A HREF= http://www.livescience.com/humanbiology/060513_skin_cancer.html class="nexthead">skin cancer</a>.
In response to the UV rays frying your inner layer of skin, your body produces more melanin pigment that darkens the skin. The pigment absorbs the radiation and protects cells from damage. Most people don't tan after just one day at the beach, or one session in the <A HREF="http://www.livescience.com/humanbiology/060328_tanning_uv.html" class="nexthead">tanning bed</a>, because it takes time to make melanin.
Damaged cells send messages to your brain, signaling they're injured and activating <A HREF="http://www.livescience.com/humanbiology/060131_pain_truths.html" class="nexthead">pain receptors</a>, which makes your skin sensitive to touch
To repair the damage and remove the dead cells, blood vessels expand and blood flow increases to the burned parts of your body. The extra blood turns your skin red and warm.
While you bake in your lounge chair, ultraviolet light from the sun zaps through your skin and kills living cells that normally work to help make new skin. Ultraviolet A, <A HREF="http://www.livescience.com/forcesofnature/050301_ozone_thinning.html" class="nexthead">UVA</a>, can travel more deeply into the skin, but both UVA and UVB rays can burn skin.