Using an electric fan in hot weather can reduce the risk of a heat-induced heart attack in the elderly, but only if its humid.
Researchers have been studying the best heat relief for older people in an environment of rising temperatures and a cost-of-living crisis which makes air conditioning less affordable.
Professor Ollie Jay from the University of Sydney said the research showed using a fan, and wetting the skin, in hot and humid weather reduced cardiac strain in older people.
However, Professor Jay said, in very hot and dry conditions, fan use had an adverse effect by tripling the increase in cardiac strain which could be fatal for someone with heart disease.
“This is because, although fans help sweat evaporate, in very hot and dry conditions the effect is small and counteracted by convection forcing more heat into the body.
“Instead, in these conditions, skin wetting used on its own was effective at reducing the work of the heart.”
Professor Jay said health hazards from extreme heat were becoming increasingly common because of climate change.
He said older adults, especially those with heart disease, were at greater risk due to the strain that hot temperatures put on the heart.
“Understanding the impacts of different cooling strategies on the heart is important to help vulnerable people stay well during hot summer weather.”
Co-author of the study Daniel Gagnon from the Montreal Heart Institute said while air conditioning was an effective way of staying cool, it was not available to everyone, especially those most vulnerable to the heat, such as the elderly and people with heart disease.
“It’s positive news that low-cost alternatives are effective,” Dr Gagnon said.
“Importantly, the study has shown that the weather conditions affect the type of cooling strategy that should be used – a vital piece of information that will help older people to stay safe in heatwaves.”
