Heatwaves are held responsible for more mortalities than any other natural disaster and people with cardiovascular, renal, respiratory and mental health problems are more likely to be affected and admitted to emergency departments.
There are also published reports that people with substance misuse (alcohol or drugs) are likely to have more adverse health repercussions during heatwaves.
While the full impacts of climate change remain unknown, there is a trend of unusually hot and dry weather conditions and more frequent prolonged periods of extreme heat.
Recent research of heatwave conditions by experts at the Flinders University has connected maximum daily temperatures with the health effects of extreme temperatures.
This study shows that people with health conditions which are exacerbated during heatwaves need to take precautions – even when individual days of extreme heat are forecast.
While the Bureau of Meteorology defines a heatwave for Adelaide as either five consecutive days where the dry bulb temperature is 35oC or greater; or three consecutive days of 40oC or greater – individual days of high temperatures should also be taken seriously, particularly by those at risk.
For example, our results showed that at temperatures above 40oC there is a significant increase in cardiovascular and mental health-related admissions to hospital emergency departments.
When individual maximum daily temperatures were examined, it showed that there were significant ED admissions for asthma and renal-related conditions at high temperatures.
Renal-related conditions also began to increase sharply after 40oC.
For asthma conditions, however, ED admissions started at temperatures of 31oC and continued to rise as the thermometer rose to 40o C and above.
In addition, people drinking alcohol or using drugs during extremely hot days and are also at greater risk of an adverse health outcome.
People need to be very careful particularly in Australia since individual hot days are more likely to occur during the festive season when people are at parties and having fun.
Drinking excessive alcohol causes dehydration but this is made worse during extremely hot days.
As well, vulnerable people in society are the very young, pregnant women and older people who routinely take multiple medications.
They need to take extra precautions on days of extreme heat, to ensure there is adequate intake of water and temperatures in air conditioned places are neither too hot nor too cold but kept at a comfortable level, in the 22oC – 25oC range.
Older people are at greater risk of developing pneumonia not only in winter but also if air conditioning is set at low temperatures in summer.
The research was carried out in four public hospitals in South Australia by Associate Professor Lidia Mayner, from the Torrens Resilience Institute at Flinders, and Professor Richard Woodman, from the Centre for Epidemiology and Biostatistics at Flinders’ School of Medicine.
