Summer's all fun and games and lemonade stands until you fall asleep in the park and get burned purple by the sun. Enter fair-skinned scientists. Researchers of Kings College London have isolated the specific molecule that causes sunburn pain. A study published Wednesday in the journal Science Translational Medicine reveals how the molecule employs immune cells to flesh exposed to ultraviolet-B rays, leading to the pain, redness and swelling associated with sunburn. In making their finding, scientists basically gave human subjects sunburns and then studied the biology of their skin under a microscope. Research on the molecule, a protein called CXCL5, may provide insight into treating other painful conditions. 

"In human biopsies we were able to demonstrate that the CXCL5 molecule is a significant contributor to sunburn pain when activated by ultraviolet radiation," said one of the study's author Stephen McMahon in a press release. "We hope that we have identified a potential target which can now be utilized to understand more about pain in other inflammatory conditions like arthritis and cystitis."

USA Today points out that this does not mean sunburns are safe:

In the long run, the researchers hope to develop a treatment for combating the pain associated with sunburns. However, whether or not a drug is made available, they will continue to discourage people from exposing themselves to the sun for prolonged amounts of time at the risk of getting skin cancer.

In related health news, misusing sunscreen can actually raise your risk of skin cancer. In unrelated news, these new glasses equipped with cameras and sensors are a step towards bionic eyes and can help the blind see. Science is amazing stuff.