One of the characteristics of tennis is that you do not know when the match is going to finish, and a 'long' match is a real possibility. Very recently, the longest match in tennis history occurred in the first round of Wimbledon 2010 between John Isner and Nicholas Mahut. A total of 183 games were played and the match lasted for 11 hours and 5 minutes (and was played over 3 days). It is well known that the match duration depends on the scoring system used. The Australian Open is played in Melbourne in the hottest time of the year, where temperatures can reach 40 degrees. Players sometimes comment on the extreme temperatures. A heat rule policy for the Australian Open was introduced by Tennis Australia in 1998 and modified a number of times over the years since. This article aims to provide insights as to how the Australian Open Extreme Heat Policy could be modifi ed by accounting for the possible match duration.