The Australian Tennis Open is conducted in every January at the Melbourne Tennis Stadium, which contains the Rod Laver Arena and Vodafone Arena now known as Hisense Arena. The Australian open tennis tournament is one of the four major grand slam tennis tournaments, the other three being the French Open in Paris, the Wimbledon in London and the US Open in New York. However, the Australian open tennis is considered one of the toughest due to the hot weather existing in Melbourne in January. Further, it is considered the first Grand Slam Tennis Tournament of the year, since it is conducted in January. The temperatures will often reach 40o and potentially the heat will be a few degrees higher than that. To help reduce the often crippling impact of the heat on players the Australian open tennis tournament organisers installed retractable roof systems over the playing areas that could be shut if the heat is extreme or if rain occurs. An Australian, Rod Laver, is the only person that had won all the four Grand Slam Tennis Tournaments in one year, twice so far in the world.