A heatwave can be defined as a prolonged period of excessive heat, often combined with high humidity. In Australia, excessive heat can vary from 37°C to 42°C. This unusual and uncomfortable hot weather can impact on human and animal health and cause disruption to community infrastructure such as power supply, public transport and other services. Heatwave conditions significantly increase the demand for electricity to power air conditioning systems which impacts on the power grid resulting in possible brown-out or even black-outs, which in turn intensifies the heatwave impact on people.
Historically, heatwaves have been responsible for more deaths in Australia than any other natural hazard, including bushfires, storms, tropical cyclones and floods (Coates 1996). Babies and young children, along with seniors and the frail within the community are more at risk and are acutely affected by heat wave conditions. he demographic profiles also indicate that a more vulnerable communities is located in Mt Cotton which is characterised by young families with a high proportion of those families with children under the age of 10 years.
Based on the demographic profiles for Redland City and the Islands of Moreton Bay there are a higher proportion of residents over the age of 65 years living in the coastal areas of Ormiston, Sheldon, Cleveland and Victoria Point. There is also a high proportion of people over the age of 55 years living on the Islands of Moreton Bay than the mainland. This fact, along with limited access to medical services on the islands, places these communities at greater risk from heatwave than that of the mainland.
While heatwaves are not unusual for Australians, the trend towards more frequent and intense heatwaves (Alexander et al. 2007) is of significant concern. McMichael et al. (2003) has estimated that extreme temperatures currently contribute to the deaths of over 1000 people aged over 65 each year across Australia. The number of heat-related deaths in temperate Australian cities is expected to rise considerably by 2050 as the frequency and intensity of heatwaves is projected to increase under climate change from global warming. For further information about coping with heatwave events go to: www.health.qld.gov.au/disaster/