What is the heat health alert system?
The Department of Health and Human Services operates a heat health alert system. The system is used to notify the department’s program areas, hospitals, health and community service providers, local councils and the general public via email about forecasted extreme heat conditions which are likely to impact human health. The heat health alert system operates annually between December to the end of February, but can be extended to responded to forecasting.
The Chief Health Officer issues a heat health alert when mean temperatures are predicted to reach or exceed heat health thresholds. The department recommends that you continue to monitor local conditions and act in line with your heat, business continuity and occupational health and safety (OH&S) plans.
Weather forecast districts
The heat health alert system uses the Bureau of Meteorology weather forecast districts and boundaries.
Heat health temperature thresholds
Temperature thresholds have been identified for Victoria, above which heat-related illness and mortality increases substantially.
These thresholds differ across the state in recognition of the higher daily average temperatures experienced in northern parts of Victoria.
The decision to issue an alert
The department monitors the Bureau of Meteorology forecast daily minimum and maximum temperatures and calculates the daily average temperature for each weather forecast district.
The average temperature for any given day is the average of the forecasted daily maximum temperature and the forecasted overnight temperature (which is also the daily minimum for the following day).
When forecast daily average temperatures are predicted to reach or exceed the heat health temperature threshold for any weather forecast district the department issues heat health alerts for that weather forecast district.
Heat health alerts
Heat health alerts are issued via the department’s email subscription service. To subscribe to receive heat health alerts and other emergency advice from the department go to: www.health.vic.gov.au/subscribe
The department recommends that you follow your organisational heat plans, once a heat health alert is issued. People in the general community should be encouraged to prepare for extreme heat to protect themselves and those in their care from the impact of extreme heat, particularly those most at risk.
The department may also consider other factors that may influence vulnerability, such as very high maximum or minimum temperatures and high temperatures over a prolonged consecutive period. High temperature alerts may be issued in these circumstances even if the average temperature threshold is not exceeded. Prolonged high temperatures below threshold levels can still impact on health.
Where possible, heat health alerts will be issued 2-3 days prior to forecast extreme heat conditions providing alert recipients with an early warning. Even though the department will be monitoring forecast temperatures across the state, it is important for local councils and other organisations to continue to monitor local weather conditions. It may be necessary for local councils to activate heat plans in the absence of a heat health alert being issued.
© State of Victoria, Department of Health and Human Services, December 2019