Paper Reviewed
Coates, L., Haynes, K., O'Brien, J., McAneney, J. and Dimer de Oliveira, F. 2014. Exploring 167 years of vulnerability: An examination of extreme heat events in Australia 1844-2010. Environmental Science & Policy 42: 33-4.

Utilizing a database of natural hazard event impacts known as PerilAUS - which was produced by Risk Frontiers (an independent research center located at Australia's Macquarie University that is sponsored by the insurance industry) - Coates et al. (2014) derived what they call "a lower-bound estimate of heat-associated deaths in Australia since European settlement." This figure for "extreme heat events" - which are also often referred to as "heat waves" - from the time of European settlement in 1844 to 2010 was, in their words, "at least 5332," while from 1900 to 2010 it was 4555.

The five researchers also determined that "both deaths and death rates (per unit of population) fluctuate widely but show an overall decrease with time." In South Australia, for example, where the death rate has been the highest, they report that "the decadal death rate has fallen from 1.69 deaths per 100,000 population in the 1910s to 0.26 in the 2000s," which is a decline of nearly 85%. And this drop in death rate has occurred, as they describe it, in spite of the fact that "the elderly are significantly more vulnerable to the risk of heat-associated death than the general population, and this vulnerability increases with age." Nevertheless, they clearly state that "death rates amongst seniors also show a decrease with time," which finding is in harmony with that of Bobb et al. (2014), who found much the same thing for the elderly in the United States, where between 1987 and 2005, the decline in death rate due to heat "was largest among those ≥ 75 years of age."

Reference
Bobb, J.F., Peng, R.D., Bell, M.L. and Dominici, F. 2014. Heat-related mortality and adaptation to heat in the United States. Environmental Health Perspectives 122: 811-816.