With everyone "feeling hot, hot, hot" at the All England Club yesterday it was little wonder Novak Djokovic and Maria Sharapova were keen to escape Wimbledon's furnace as soon as possible. It was the hottest day of the year in Britain - with the mercury hitting 34ºC.Champion Djokovic was spared the worst of the heat on the partly covered Centre Court as he kept things simple in a 90-minute 6-4 6-2 6-3 second-round demolition job that ended the Wimbledon career of seasoned Finn Jarkko Nieminen.Fourth seed Sharapova survived the embarrassment of firing down three successive double faults to surrender her serve at 4-2 up in the first set.She turned on the heat to win eight of the next nine games and subdue Dutchwoman Richel Hogenkamp 6-3 6-1.Sharapova's boyfriend, Grigor Dimitrov, the 11th seed, outlast ed American Steve Johnson 7-6(8) 6-2 7-6(2).Fifth seed Kei Nishikori spared his battered body further punishment in the searing conditions after he pulled out of his second-round match against Santiago Giraldo with a calf strain.Nishikori was not the only one needing medical attention on day three of the championships as a ballboy had to be wheeled off Court 17 after collapsing during American John Isner's 6-2 7-6(8) 6-4 win over Australian Matthew Ebden.Milos Raonic was kept on Court One longer than he would have liked by the oldest man in the singles draw.At 37, Tommy Haas proved that his patched-up body still had the ability to fight it out with the best even when he is under heavy bombardment.The German managed to snatch the third set but Canadian seventh seed Raonic hurled down 29 aces, including one clocked at 145 miles per hour, to secure a 6-0 6-2 6-7(5) 7-6(4) victory. ..