Extreme heat growing health issue; killed 356,000 people in 2019: Study

High temperatures linked to heat stroke, hospitalisations and mental health issues, say researchers.

More than 356,000 people died in 2019 as a result of extreme heat and that number is likely to grow, according to a study published in The Lancet this week.

The Global Burden of Disease review, funded by the Bill & Melinda Gates Foundation, found while cold temperatures still cause a greater number of deaths, mortality rates attributable to heat are growing faster, particularly in hotter regions of the world.  

“This is very concerning, particularly given the risk of exposure to high temperatures appears to have been increasing steadily for decades,” said co-author Katrin Burkart from the University of Washington.  

The findings echo another report, a two-part series called “Heat and Health” that was also published in The Lancet this week. It calls for global warming to be limited to 2.7 degrees F, in line with the Paris Climate Accords, to reduce heat-related mortality in the future. Otherwise, deaths will increase further and extreme heat will also lessen worker productivity and exacerbate other environmental challenges, such as wildfires, researchers said. 

“The effects extreme heat exposure can have on the body present a clear and growing global health issue,” said Ollie Jay, a professor from the University of Sydney, and a co-author of the Heat and Health report.

In addition to causing heat stroke, high temperatures have been linked to increased hospitalizations and mental health issues. Older people and other vulnerable groups, such as those with low mobility, are likely to be more at risk. High temperatures can also reduce productivity. Around 1 billion workers, many engaged in manual labor, often report lower output due to heat stress. 

Even with strategies to slow climate change and reduce carbon emissions, environmentally sustainable changes need to be made to adapt to an increasingly hotter world. Measures that can be taken to mitigate the heat’s worst effects on health include increasing the amount of green space in cities, putting wall coatings that can reflect heat on buildings, and using more cooling and misting fans. While air-conditioning is becoming more available, not everyone can afford it and it can harm the environment. 

“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,” said Kristie Ebi, a professor from the University of Washingon and co-lead author of the Heat and Health study.