Excessive heat has marred the annual T in the Park festival in Scotland for some revellers, with medical staff onsite treating almost 900 people for mainly sun-related issues. While arrests are down to 57 since the event opened on Thursday (11Jul13), medical needs have spiralled as music fans ignored warnings to drink plenty of water and cover themselves with lotion. Medical experts have revealed most of the issues they have dealt with over the weekend have been connected to dehydration and sunburn. T in the Park concludes on Sunday night (14Jul13) with headline performances from The Killers and Frank Ocean. Rihanna topped the bill at the festival on Saturday night (13Jul13) after appearing onstage 15 minutes late. Alt-J, Ke$ha and Liam Gallagher's Beady Eye also performed.