Heat guidelines

Implementation of the World Rugby Heat Guidelines

In extreme weather conditions, an objective assessment of the environment may be required to assist in determining the safety of the prevailing conditions.

Game Day Interventions should be implemented once the Heat Stress Index (HSI) is above 150. The HSI is determined using a combination of temperature and humidity (see graph in World Rugby Heat Guidelines PDF).

If practical, training and playing should be scheduled when ambient temperatures, radiant heat (direct sunlight) and humidity are expected to be at acceptable levels. Utilising the Heat Stress Index, a guide to acceptable levels would be:

  • temperature ≤ 30 degrees Celsius
  • humidity ≤ 60%

There is no evidence to suggest training or playing at higher temperature and humidity levels will result in a heat illness.


  • The MDD should meet with the two Team Doctors to discuss the weather conditions. If any of the doctors at the meetings have a concern over the conditions, then move to step 2.
  • The MDD should perform the “Whirling Hygrometer” test to establish the HSI.
  • If the HSI is above 150, it is recommended that all of the Heat Illness Prevention Interventions as listed in the World Rugby Heat Guidelines be implemented.
  • The MDD should then meet with the match manager and referee to inform him of the information and recommendation.
  • Once a position is agreed (especially with relation to proposed water breaks), the match manager will inform the following parties of the water breaks:
    • Confirm with all match officials
    • Both team managers
    • Ground announcer
    • Event staff
    • Broadcaster floor manager
  • This is an independent process run by the MDD in consultation with both Team Doctors. The decision to implement the Game Day Interventions lies with the MDD and, if no MDD, then the referee.

View Guidelines

Download the World Rugby Heat Guidelines as a printable Adobe PDF file