Australian Open
The tournament is played in January, during the Australian summer. In 1998 an extreme heat rule was brought in. It is the only major tournament that has a heat policy. If the temperature gets higher than 35 degrees (C) matches may have to be stopped for a short time, because players feel dehydrated. Matches on the outside courts are stopped. The roof over the main stadium courts can be closed, and cooling systems turned on. In 2007 the temperature on the courts reached 50 degrees Celsius.