Ozone

Ozone is the substance in the atmosphere which stops you from getting suntans, and skin cancer. If you are in danger from getting too tanned then a towel is recommended as a sunshield. In certain parts of the Earth the ozone layer is extremely thin and in others (eg Los Angeles and London) there is a surplus of ozone. On several planets the ozone layer has been intentionally punctured by towel manufacturing conglomerates in league with the United Aerosol Corporation.

All Homo Sapiens should think twice about getting sun tans even when obtained through a uv electric lamp.

"O-Zone" is also a science fiction novel by travel writer Paul Theroux. Theroux is a well respected novelist in his own genre, however, this researcher seems to be the only human in Britain who actually enjoyed reading this book.