Museum of Science and Industry

Summer has a lot of great things: fireworks, pools, barbecues and great weather. However, there is a bad part about spending all that time outside: sunburns.

One can imagine that there have been sunburns for as long as we've had skin. While we've learned a lot about how the sun's UV rays damage the skin, little has been known as to why overexposure turns it into a red painful mess. That is, until now. A team at UC San Diego found that when a cell is damaged by UV rays from the sun, the cell's RNA breaks into little pieces. Receptors in neighboring cells detect this, and instruct the skin to inflame. TA-DA! Goodbye regular skin, hello ouchie-filled aloe applications.

So why do we sunburn? That inflammation causes the body to get rid of the cells damaged by the sun, possibly to clear out potentially cancerous ones. And the pain we feel serves as a reminder to wear more sunscreen or stay in the shade. So you might want to listen to your body's warning. That is, unless you prefer to look like a lobster. 

Mystery Solved: Why We Sunburn [National Geographic]

Image: iStockphoto