Levels of UV rays can vary. A two week holiday in the Mediterranean will expose you to the same amount of sun as you would get in a year in Britain. Short periods of intense exposure to the sun are thought to be more risky than regular daily exposure, particularly if you have fairer skin. However, even if you have darker skin tones you will burn eventually. You can find out the daily UV rate by watching the solar UV index which has recently been introduced on national weather forecasts across Europe.