Extreme heat is becoming a growing global health issue responsible for thousands of unnecessary deaths, a new study has warned.
Researchers say that urgent action to mitigate climate change is needed to prevent more adverse effects on health, with recommendations including changes to infrastructure, urban environments and human behaviour.
The peer-reviewed report, published in the Lancet on Thursday, has been released ahead of the Cop26 global summit being held in Glasgow later this year.
World leaders and climate activists will meet in November to outline the steps required to meet a 1.5°C global warming target set by the 2015 Paris Agreement.
Meeting this goal is crucial to reducing the number of heat-related deaths, the report's authors say.
Extreme temperatures are associated with increasing hospital admissions and emergency room visits, adverse pregnancy and birth outcomes, and increased health care costs, the report says.
More than 356,000 people died due to extreme hot weather in 2019, many of whom were elderly or vulnerable, the Lancet study says, quoting modelling from the Global Burden of Disease.
Additionally, surging global temperatures are responsible for declining work productivity, especially among the more than one billion workers who are exposed to high heat on a regular basis.
Specific strategies can help reduce exposure to heat stroke and other illness caused by high temperatures, according to co-lead author Professor Kristie Ebi, of the University of Washington.
“Two strategic approaches are needed to combat extreme heat," Professor Ebi said. "One is climate change mitigation to reduce carbon emissions and alter the further warming of the planet. The other is identifying timely and effective prevention and response measures, particularly for low-resource settings.
"With more than half of the global population projected to be exposed to weeks of dangerous heat every year by the end of this century, we need to find ways to cool people effectively and sustainably.”
The report warns that daily summer activities – such as exercising and working outdoors – could change dramatically as increasing warming leaves people at greater risk of exposure to intolerable heat.
It outlines a number of strategies to combat a rise in temperatures, including increasing the green space in cities, wall coatings that reflect heat from buildings and widespread use of electric fans and other cooling measures.
“It is critical that the personal cooling strategies we recommend in heat-health action plans are based on scientific evidence," co-lead author Professor Ollie Jay, of the University of Sydney, said. "Too many strategies that are recommended in some existing heat-health action plans seem to be based on conventional wisdom.
"For example, it is commonly recommended that sugary drinks and high-protein meals are avoided, and that fans should not be used, yet studies demonstrate the cooling effectiveness of fans at higher temperatures and other strategies such as self-dousing with water or wearing wet clothing.
"Early warning systems for extreme heat events, including evidence-based measures to protect vulnerable populations and raising awareness of the health risks posed by heat, will be central to limiting ill health and deaths from heat events, today and in the future."