Ask A Scientist General Science Archive

name         Laura A.
status       student
age          13

Question -   Why does your skin turn red after getting a sunburn?
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Because your skin is burned.  Heat is not the only thing that can burn your
skin. Chemicals and radiation can also.  It is possible to get second degree
burns from the sun.

vanhoeck
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The red of skin burn or a cut or bruise is the inflammatory response the body's
immune system gives when there is damage to the body, in this case the skin.  
The heat feeling is also part of that same response for the blood vessels enlarge
near the skin's surface in order for the white blood cells to fight off foreign
invaders and to help remove dead cells, AND to give all the nutrients (etc.) for 
repairing the damage tissues.  Skin damage is serious for the UV rays of the sun 
that actually causes the burn damage, also does damage to the DNA of the skin cells.  
Many of these damaged cells lose the ability to control their reproduction and functions.
When you are young, the body's ability to compensate for this damaged
DNA is often enough to circumvent the onset of melanoma (skin cancer).  However,
as you age, the bodies ability to work efficiently begins to decline, often leading to the
point of the skin developing this cancer, EVEN IF THE SKIN WAS DAMAGED DECADES
PREVIOUS to the cancer's actual development.

The bottom line is that sun screen is absolute necessary to prevent this from 
occurring if you are out in the sun for long periods of time.  Newspapers often list
how long it takes to burn on any given day.  People who try to tan or get sun 
burned at any time in their lives are at a high risk.  Datas shows that it does 
not take but two or three sun burn incidents to be at risk.  
Smoking appears to amplify this risk.

Steve Sample
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