(digitalspy.co.uk) - Madonna has vowed that she will do "everything" to keep her youthful looks, according to a report.Sources close to the Queen of Pop, who turns 50 in August, have claimed that she has become increasingly paranoid about her appearance as her next birthday draws closer."All you have to do is stand within six feet of Madonna these days to see how much work she's had done," one associate told the Daily Mail. "Her skin is so stretched and thin that it's almost translucent when she doesn't have make-up on. "She's paranoid about the sun as a result - when she goes to the beach, she covers up from head to toe. And she's obsessed with radiators. They tend to dry out the skin, which ages you prematurely, apparently. Wherever possible, she has underfloor heating instead. "Of course she knows she'll get old eventually, but she's determined to do everything to fight it."