MELBOURNE, Australia (AP) — As extreme temperatures were forecasted for Saturday, the Australian Open took proactive measures by starting matches an hour earlier than usual on all courts at Melbourne Park. The anticipated rising heat warranted the implementation of the tournament's Extreme Heat Protocol, which assesses environmental conditions to safeguard players' health.

The Australian Open introduced the Heat Stress Scale in 2019, categorizing heat levels from 1 to 5 based on four climate factors: air temperature, radiant heat, humidity, and wind speed. This system was designed to create a consistent approach for managing heat-related risks and interventions during the tournament.

The protocol sets specific thresholds for cooling interventions. When conditions become excessively hot, the tournament referee has the authority to suspend play or authorize additional cooling breaks for the players. Play is automatically suspended when the Heat Stress Index reaches 5 for both men’s and women’s singles matches.

In cases of extreme heat, the referee can also suspend the scheduling of any upcoming matches on outdoor courts. If play has been halted on outdoor courts, the referee can decide whether to close the roof of the arena courts or to keep it closed for any forthcoming matches. Players are required to receive at least a half-hour notice before the resumption of play.

When the Heat Stress Index hits 4, organizers have the discretion to implement an additional 10-minute break between the second and third sets for women’s singles and between the third and fourth sets for men’s singles. However, if the roof of the arena stadium is closed before the end of the first set in a women’s singles match or before the end of the second set in a men’s singles match, no extra cooling breaks will be granted.

On Day 7 of the tournament, the humidity was relatively low at around 20%, which slightly decreased as the temperature approached 35 degrees Celsius (95 Fahrenheit) by around 1:30 p.m. local time when the Heat Stress Index reached level 4. In response to these conditions, tournament organizers recommended that spectators wear hats, apply sunscreen, stay hydrated, utilize shaded areas, and allocate extra time for their arrival at the venue.

In summary, the implementation of the Extreme Heat Protocol at the Australian Open reflects the organizers' commitment to ensuring the safety and well-being of both players and spectators during extremely hot weather conditions.