HEATWAVE WARNING: WHY WOMEN FACE A HIGHER HEART RISK WHEN THE MERCURY SOARS
With a heatwave warning in place for Queensland this weekend, new research is a timely reminder that hot weather is about far more than sunburn and sticky nights.
A study presented in Chicago this weekend has found that serious heart emergencies climb as the temperature rises, and women appear to be especially vulnerable.
The findings were shared at the American Heart Association's Resuscitation Science Symposium, held on November 7 and 8 alongside its major annual heart conference.
What the heatwave heart study found
Researchers looked at more than 11,000 people who had a cardiac arrest outside hospital and were then admitted to intensive care across 10 American health systems between 2018 and 2024.
A cardiac arrest is when the heart suddenly stops pumping blood effectively, which is different from a heart attack, although the two can be linked.
The team, led by Dr Peter Graffy from the University of Chicago, compared admissions on very hot days with those on milder ones.
Admissions rose steadily with the heat.
Compared with a day of about 29 degrees Celsius, admissions were 45 per cent higher at around 33 degrees and about double at roughly 37 degrees.
Women had a 33 per cent higher admission rate on extreme heat days, defined as above about 32 degrees.
Adults aged 65 and over were also hit hard, with a 48 per cent higher rate on hot days than on mild ones.
You can read the full summary on the American Heart Association newsroom.
Some reassuring news
Interestingly, people admitted during hot spells were no more likely to die in hospital than those admitted on cooler days.
Dr Graffy said the team was surprised the outcomes "were not that different between the two groups".
It is worth remembering this is early research that has not yet been published in a peer-reviewed journal.
It also shows a link rather than proof that heat directly causes cardiac arrest, and it comes from the United States, so results may differ here.
Why this heatwave season matters in Australia
The Bureau of Meteorology issued a heatwave warning for Queensland on Friday November 6, running until Monday November 9, as shared by Cook Shire Council.
Earlier in the week, Weatherzone reported that Brisbane was forecast to hit about 36 degrees, close to its hottest day of the year, while parts of inland Queensland were tipped to reach 42.
In Western Australia, WA Country Health Service also issued an extreme heat alert for parts of the Pilbara this week.
Health authorities say older people, babies, young children, pregnant and breastfeeding women and anyone with a medical condition are most at risk in the heat.
Simple ways to stay safe in a heatwave
Keep drinking water throughout the day, and go easy on alcohol and caffeine, which can make dehydration worse.
Close windows and draw blinds or curtains early in the morning to keep the heat out.
Use a fan or air conditioning if you have one, or spend the hottest part of the day somewhere cool such as a library, community centre or shopping centre.
Wear a hat, sunglasses, sunscreen and loose, light clothing when you do head out.
Check in on older parents, neighbours and friends who live alone, because a quick phone call can make a real difference.
Never leave a person or a pet in a parked car, even for a few minutes.
Know the warning signs
The American Heart Association points out that about 70 per cent of cardiac arrests happen at home, so learning CPR is one of the most useful skills you can have.
If someone collapses and is not breathing normally, call triple zero (000) straight away and start CPR.
If you feel dizzy, confused, nauseous or have chest pain in the heat, rest somewhere cool and seek medical help quickly.
If you have a heart condition or take regular medication, it is a good idea to speak to your GP before summer about how to manage hot days.
