MELBOURNE, Australia — On a day when shade was a valuable commodity in the searing heat at Melbourne Park, Roger Federer played it cool at the Australian Open. Six-time champion Novak Djokovic, however, complained about the brutal conditions during his 4-6, 6-3, 6-1, 6-3 second-round win over Gael Monfils, when the temperature peaked at 104 degrees Fahrenheit. Djokovic, saying the conditions were some of the toughest in which he’s ever played, urged organizers to be more flexible about the rules for drink breaks, time between points and suspension of play when the conditions were at the point where it becomes a “danger in terms of health.