Extreme cold or heat warnings need to become more specific, Monash University researchers in Melbourne say.
Their call follows the publication of a 20-year global study into 46 million exposure-related deaths across 10 countries, including Australia.
The study was just published in the prestigious 203-year-old Lancet medical journal; it found that that 4.4% of deaths from 2000-19 in these countries could be tied to short-term exposure to extreme temperatures.
Its global analysis of temperature-related deaths to different diseases, age groups, and sexes by researchers Dr Bo Wen and Professor Yuming Guo identified three exposure response patterns:
• higher risks of dying from extreme cold for most causes;
• equal risks of dying from either extreme temperature for respiratory mortality;
• higher risks of dying from extreme heat for injuries and external causes.
EXTREME RISKS VARY
It also found that the most affected diseases were mental health disorders (6.53%), nervous system diseases (6.40%) and cardiovascular conditions (5.71%).
But the research reveals the risks were not the same for everyone, according to Dr Wen.
“We found that older adults were more vulnerable to cold-related nervous system diseases and neoplasms (cancers) while younger individuals were more affected by heat-related risks for injuries and external causes,” he says.
“This study shows that public health strategies need to move beyond general warnings about heat or cold and instead focus on specific diseases and vulnerable groups.”
The study covered 1117 locations in Australia, Brazil, Canada, Chile, Mexico, New Zealand, Philippines, South Korea, Taiwan and Thailand.
Over the 20 years, researchers estimate that 2.03 million deaths were due to extreme temperatures (or 4.38% of all deaths in that time) with cold identified as the most common cause in these deaths as heat accounted for most deaths from infection, injury and other external causes.
Prof Guo says the study is the largest to date that classifies cause-, age-, and gender- mortality risks by extreme temperature.
“Critically, differences in temperature-related mortality risks were observed between subgroups of age and sex,” Professor Guo says, “with the impact of cold and heat varying across causes of death.”
To read their paper, click here: www.doi.org/10.1016/j.eclinm.2026.103920
MORE TEMPERATURE STORIES: 2023 Atlantic heatwave flipped the rules
