Heat and humidity proved to be a key topic of discussion during the Tokyo 2020 Olympic Games, and will be once again at the Paralympic Tennis Event – indeed, on Day 1 of the competition, play on all outside courts was suspended prior to the first matches in line with the Extreme Weather Policy. 

So how does the Extreme Weather Policy differ at the Paralympic Games, and what happens when it comes into effect? Here’s your one-stop guide to the policy in action… 

What is ‘extreme weather’? 

In tennis, ‘extreme weather’ typically refers to the heat and humidity players are dealing with on court – though other forms of extreme weather can also prompt action from the tournament referee. 

Heat and humidity is monitored using the Wet Bulb Globe Temperature, a measure of heat stress in direct sunlight which also takes into account wind speed, cloud cover and the angle of the sun. 

The West Bulb Globe Temperature (WBGT) is measured in Celsius or Fahrenheit – the ITF delivers its monitoring reports in Celsius. WBGT temperatures are taken each day, every 30 minutes during the Paralympic Tennis Event, starting at 10:00am local time. 

The WGBT threshold is lower for wheelchair tennis players – while for the Olympics the first threshold for action was 30.1°C, at the Paralympics the threshold is 28.0°C. Once that mark is reached, the Extreme Weather Policy comes into effect. 

What happens next? 

There are two options available to the tournament referee once the Extreme Weather Policy comes into effect. The first is modification of play, implemented at 28.0°C.  

Chair umpires are instructed to inform the players promptly so that they are aware the policy is active: this happens either immediately before the match or, for those matches under way when the policy comes into effect, at the next change of ends. 

‘Modification of Play’ introduces a 20-minute break between the second and third sets at the request of either player – twice the length of the 10-minute break at the Olympics. If neither player wants to take a break, the match may continue.  

Should the Extreme Weather Policy be lifted while players are on court, any matches currently in play will continue with the policy in place until completed. 

If a match is suspended for 20 minutes or longer prior to the end of the second set, the WGBT reading at the resumption of play will determine whether or not the Extreme Heat Policy is active – and if the first set had been completed prior to suspension, there will not be a 20-minute break between the second and third sets when play resumes whether or not the policy is in effect. 

What is allowed during the 20-minute break? 

Players may leave the court for up to 20 minutes after the second set, returning to be ready to begin the third. The chair umpire will call time after 19 minutes, 30 seconds to indicate that players should be ready to resume play shortly afterwards. If a player does not return to court, they will be subject to time violations – whether serving or receiving. 

While off-court, players can: 

• Go to the bathroom
• Take a shower
• Change their outfit 
• Have something to eat or drink 
• Adjust any medical straps or get re-taped 

However, they cannot: 

• Receive a medical evaluation, take a medical time-out or receive any treatment unless approved by the tournament referee or supervisor 
• Talk with their coach, or receive any coaching 
• Use electronic devices 
• Take a further break to go to the bathroom or change their outfit, extending the 20-minute break 

 
What if the WBGT continues to rise? 

Once the Wet Bulb Globe Temperature hits 30.1°C, the tournament referee enacts the second option available via the Extreme Weather Policy: suspension of play.  

All matches that are not yet under way – which includes those still to complete the warm-up – are suspended and the players directed from the court to await further updates. For matches that are in progress when this second threshold (called the Extreme Heat Condition) is met, play is suspended at the end of the current set. 

There is a third option available if the WGBT continues to rise: immediate suspension of play, which comes into effect at 32.2°C in wheelchair tennis. In this scenario, any matches in progress on the outside courts will be suspended once an even number of games have been played in the current set. If the players are involved in a tiebreak, the match will be suspended once it is completed. 

Once the conditions drop below the Extreme Heat Condition parameters, the referee will give the players reasonable notice about when play will resume. 

The Ariake Tennis Park Centre Court has a retractable roof and climate control, which allows play to continue with the roof closed. Like the action on the outside courts, any match in progress will be temporarily suspended after an even number of games in the set, or after a tiebreak, to allow the roof to be closed. After that, it will stay closed for the remainder of the match in progress. 

 
Why not start play later, when it may be cooler? 

There are many factors to consider when scheduling a tennis event. For instance, anyone who follows the sport knows how susceptible outdoor tournaments are to the elements - rain, specifically, which is also a potential factor in Tokyo. 

Then there is the matter of time. Tennis matches have no set time limit, and can often run beyond two hours and in some cases three hours, so an early start time presents the best chance of completing all of the day's matches. Many players are also involved in multiple events, and factoring in time for suitable rests between matches must also be considered And tennis is part of a multi-sport schedule at the Paralympic Games, with six medal events taking place over nine days.  

Delaying the start of play is also complicated earlier in a tournament, when the number of matches that must be completed to ensure the event can end as scheduled is at its highest. During the Olympics, when the opportunity to move the start times until later in the day without risking significant delays at the end of the tournament presented itself, all subsequent start times were moved to 15:00. 

There are also local protocols to take into consideration. The Tokyo 2020 organisers have a 23:30 curfew in place so that local staff and volunteers are able to use public transport to return home. With reduced staff on site, play is still possible on a small number of courts should matches run late, but not all.

Scheduling will always be problematic when dealing with extreme conditions, but decisions are ultimately made to protect player health and welfare.  

Why is it called the Extreme Weather Policy, and not the Extreme Heat Policy? 

Because there’s other extreme weather out there! Another potential factor in Tokyo will be thunderstorms and the possibility of lightning strikes, which would also result in the suspension of play until the weather system has passed.