Planning for a heatwave

Richard A. Broome, Deputy Director of Environmental Health

Watch Dr Richard Broome, Deputy Director Environmental Health, talking about heatwaves

Richard A. Broome, Deputy Director of Environmental Health

The profound public health impact of prolonged spells of hot weather became acutely apparent in 2003 when Europe experienced its hottest summer since 1540. As the whole continent sweltered, temperatures reached 38°C in the UK and Holland, 40°C in France and 47.4°C in Portugal. The devastating health effects that these temperatures had were immediately obvious.

Bodies began to pile up, refrigerated warehouses had to be converted to temporary morgues and, tragically, many people returned from their summer holidays to find their elderly friends and relatives had died.[1]

Since this disaster, the World Health Organization (WHO) has estimated the whole event caused 70,000 deaths.[2]

Australia has also suffered the effects of heatwaves. In January 2009, the south east of the country was affected by a week-long period of exceptionally hot weather. Not only did this cause several hundred deaths but it also led to widespread heat-related failure of power and transport infrastructure.[3]

In early 2011, a heatwave of record breaking duration affected Sydney, causing an estimated 104 and 236 emergency department visits for heat effects and dehydration respectively and 116 ambulance calls for heat exposure (figure 3). All-cause mortality increased by 13% [4] and studies conducted in Sydney have shown an increase in mortality [5] and hospitalisations [6] on days above the 95th percentile temperature.

Events such as these have generated a great deal of research into the health impacts of heatwaves. The results of this research guide the development of heatwave response plans that aim to prevent or mitigate the health impacts of hot weather.

The WHO recommends the following key components of a heatwave response plan:[7]

  • a lead agency to coordinate the response
  • an early warning system
  • a heat-health information system
  • a focus on vulnerable people
  • strategies to reduce individual and community exposure to heat
  • umproved urban planning, transport policies and building design to reduce energy consumption
  • provision of health care, social service and health infrastructure
  • real-time surveillance, evaluation and monitoring.

NSW has a heatwave response plan (the NSW Heatwave Sub Plan),[8] which was completed in late 2011 and has since been activated on two occasions. This plan identifies the State Emergency Operations Controller as having overall responsibility for coordinating any response to a heatwave. It also describes the roles and responsibilities of individual agencies such as NSW Health, Transport for NSW and local government.

Figure 3 Effects of the 2011 Sydney heatwave on ED visits and ambulance callouts, from Schaffer et al, 2012 

Under this plan, NSW Health has developed an early warning system that it uses to alert other agencies and the community of impending heatwaves. NSW Health has also developed a heat-health information website that provides comprehensive advice on the nature of heat-related illness and describes simple preventive measures for members of the public, those who care for vulnerable community members and healthcare professionals.[9] NSW Health’s real-time emergency department surveillance system (PHREDSS) has been used on several occasions to monitor the impact of heatwaves.

Future strategies involve ongoing collaboration with other state and local government agencies to identify better ways of providing support to vulnerable people and groups and to develop community-wide strategies to reduce heat exposure.


  1. Clare Murphy. Corpses prompt French soul searching. BBC News. 26 August 2003. url: (accessed 11 March 2014).
  2. Robine JM, Cheung SLK, Le Roy S, Herman VO, Griffiths C, Michel JP, Hermann FR. Death toll exceeded 70,000 in Europe during the summer of 2003. Compte Rendus Biologies 2008, 331(2) 171-8
  3. Queensland University of Technology. Impacts and adaptation response of infrastructure and communities to heatwaves: the southern Australian experience of 2009, report for the National Climate Change Adaptation Research Facility 2010, Gold Coast, Australia
  4. Schaffer A, Muscatello D, Broome R, et al. Emergency department visits, ambulance calls, and mortality associated with an exceptional heat wave in Sydney, Australia, 2011: a time-series analysis Environmental Health 2012, 11(3)
  5. Wilson LA, Morgan GG, Hanigan IC, Johnston FH, Abu-Rayya H, Broome R, Gaskin C, Jalaludin B. The impact of heat on mortality and morbidity in the Greater Metropolitan Sydney Region: a case crossover analysis. Environmental Health 2013, 12(98)
  6. Vaneckova P, Bambrick H. Cause-specific hospital admission on hot days in Sydney, Australia. PLoS ONE 2013, 8(2):e55459
  7. World Health Organization Regional Office for Europe. Euroheat: Improving public health responses to extreme weather/heat-waves – summary for policy makers, World Health Organization 2009, Copenhagen, Denmark
  8. NSW State Emergency Management Committee. Heatwave Sub Plan. NSW State Emergency Management Committee 2011, Sydney, Australia
  9. NSW Health. Beat the Heat Website, NSW Health url: (accessed 11 March 2014)
Current as at: Monday 26 May 2014
Contact page owner: Health Protection NSW