Heatstroke Statistics Worldwide 2024

Heatstroke Statistics Worldwide 2024

There was a 74% increase in heat-related deaths between 1980 and 2016 and, in 2019, more than 356,000 people in nine countries died from extreme heat-related causes. These figures, from recent studies published in The Lancet, are only some of the many statistics highlighting the seriousness of heatstroke and other dangerous conditions linked to exposure to high temperatures. Far from only affecting people in the world’s hottest regions, heatstroke can affect people who work in hot environments, such as foundries, construction sites, mines, farms, oil rigs and warehouses.

This article explores data gathered by Polly from 353,181 people over a 12-month period ending on 8 April 2024. The data gathered people’s responses to various heatstroke-related situations online across platforms like X, TikTok and Reddit, offering more insights into the topic and its talking points. Here’s what the data revealed.


Deaths caused by heatwaves by country

According to the World Health Organization, more than 166,000 people died due to heatwaves between 1998 and 2017. Due to climate change, temperatures are rising across the globe, and population exposure to heat is increasing concurrently. Between 2000 and 2016, the number of people who were exposed to heatwaves increased by approximately 125 million.

Currently, Europe statistically has the highest number of deaths as a result of heatwaves. When broken down into mortality rates, Italy has the greatest number of heat-attributable deaths, followed by Greece, Spain and Portugal. The USA has also seen a significant increase in the number of heat-related deaths due to heatwaves. 

Heatwaves have become one of the deadliest extreme weather events and, while death tolls are often under-reported, especially in countries like India, Cambodia, the Philippines and Thailand, it’s clear that, as the world gets hotter, greater measures are needed to protect vulnerable citizens or those working in industries where heat exposure is commonplace.


Deaths caused by heatwaves globally each year

In 2003, more than 70,000 people died during the European heatwave. Unfortunately, extreme temperatures are a major cause of death in Europe, but this country is certainly not the only one affected. According to a study in The Lancet, in 2019, more than 356,000 people died in nine other countries from causes related to extreme heat.

In the US, more recent data also reveals an increase in deaths caused by extreme heat. According to figures from the U.S. Department of Health and Human Services, there were approximately 1,602 heat-related deaths in 2021, 1,722 in 2022 and 2,302 in 2023. 

In 2023, an increased number of heatstroke deaths and other heat-related deaths were also reported in Mexico, Algeria and China, among other countries. It’s now estimated that climate change’s exacerbation of heatstroke and heat-related causes of death could see global heat deaths increase by as much as 370%


Excessive heat exposure: The primary cause of heatstroke

Heatstroke can happen when the body’s temperature rises to 40°C / 104°F or higher. The root cause of heatstroke is prolonged exposure to high temperatures in which the body can no longer control its own temperature, leading to its overheating.

Discover what Polly’s data reveals about what people are saying are the leading causes of heatstroke below.

According to Polly, 45% of people said their heatstroke was caused by excessive exposure to heat. While weather is a major factor here, those working in construction or industrial environments are also subject to high temperatures. Oil rig workers, those working on roads, roofs or in iron and steel mills and foundries, and other factory employees exposed to heat from furnaces or ovens, are all extremely vulnerable. Emergency workers, such as firefighters, are also at high risk.

Coming in just under excessive exposure to heat, 41.4% named high humidity as the cause of their heatstroke, 6.8% cited dehydration, while 3.2% said a lack of shade or shelter was the main cause. 

According to 1.8% of those who engaged, prolonged sun exposure was a cause, 1.2% named lack of acclimatization, while 0.4% said underlying health conditions caused heatstroke. Only 0.2% talked about strenuous physical activity causing their heatstroke.

An increase in hot summer days linked to climate change is one of the reasons for the high number of deaths linked to heatstroke in the USA, but this is far from being the only reason. Among other factors at play are working outdoors, working indoors without sufficient mechanical cooling or ventilation, methamphetamine abuse, living in urban areas without adequate tree cover, wearing excess clothing, and becoming dehydrated or drinking alcohol while performing strenuous activity indoors or outdoors.


Cool showers: The most common recovery option

Not all cases of heatstroke are fatal. See below what Polly’s data reveals about what people said they did to recover from heatstroke.

Of the people surveyed, 34.3% said they recovered by taking cool showers, while 33.4% said wearing light clothing helped with heatstroke recovery. Some 13.7% said they avoided direct sunlight, while 6.4% avoided strenuous activity; 5% confirmed that medical attention helped and 3.5% said air conditioning supported their recovery. Only 1.8% named hydration as an aid, while 1.1% opted to use a fan, 0.5% referred to other cooling measures and 0.2% referred to rest as a way to recuperate.

Several of the methods mentioned align with the U.S. Department of Labor’s Occupational Safety and Health Administration’s (OSHA) first aid recommendations for heatstroke and other heat-related illnesses. These include taking the worker to a cooler area, such as with shade or air conditioning, and cooling them by immersing them in cold water or an ice bath, removing outer layers of clothing, placing cold wet towels or ice on their head, neck, armpits, trunk and groin, and using fans to circulate air around them. 


Over 65s are most affected by heatstroke

Polly’s data sheds light on which age groups were most affected by heatstroke.

Find out below if online engagement levels are in keeping with the age groups most impacted by heatstroke deaths.

According to Polly, the over-65 age group suffered from heatstroke the most at 32.3%, followed by the 45-54 age group with 18.6%. In third place were those aged <25 with 18%, followed closely by the 55-64 age group at 17.7%. The groups aged 35-44 and 25-34 had the least sufferers, with 8.7% and 4.6% respectively.

These levels of engagement were relatively similar to a 2022 CDC report. The report found that the age group with the highest number of heat-related deaths in the period 2018–2020 was 55-64; however, from age 65 to 85 and older, there was a gradual decline.  


The USA has the most heatstroke survivors at 87.7%

Polly focused on data from several countries to see which had the highest number of heatstroke survivors. The graph below shows how the countries stack up.

According to Polly’s data, the US had the highest level of heatstroke survivors, with 87.7%. This high figure aligns with the Occupational Health & Safety magazine report that states that every day in the US, 11 workers are seriously injured or die from heat stress. The other countries listed had significantly fewer surviving heatstroke victims, with only 4.3% in Australia, 3.5% in the UK, 3% in Canada, 0.9% in France and 0.5% in Germany.

Polly’s data on Australian survivors is surprisingly low, considering a recent study found an increase in the number of Australians admitted to hospital due to extreme heat in the last decade. The report found that 78% of all injury hospitalisations (and 43% of all injury deaths) in a ten-year period were a result of extreme heat.

The relatively low number of heatstroke survivors in the UK among the sample is also surprising, as heatstroke has become a major issue in this part of the world. In the summer of 2022 alone, there were an estimated 2,985 all-cause excess deaths associated with five separate heat episodes. Engagement around heatstroke in Canada, France and Germany was also disproportionately low. In Canada’s British Columbia province, 600 people died during a 2021 heatwave. In France, more than 5,000 people died during a 2023 heatwave, and, in Germany, there were approximately 3,200 heat-related deaths in the first nine months of 2023. Based on these numbers, the expectation would be that a greater number of people also suffered and survived, rather than there being such a huge jump between the US and other countries. 


Middle-income earners suffer the most from heatstroke

To the average person, income isn’t a factor they would associate immediately with instances or risk of heatstroke. However, some economic groups are more at risk of heatstroke than others. Let’s see what Polly’s data reveals.

According to Polly, those who were hit the hardest by heatstroke (41.4%) earned between $120,000 and $200,000, followed by the 24.1% who earned between $40,000 and $80,000. Those hit the least hard (3.1%) earned over $1 million, closely followed by the 4.7% earning $80,000 to $120,000.

With the exception of the $40,000 to $80,000 group, some income groups’ engagement levels are disproportionate to the number of heat injuries and heatstroke deaths they experience. Analysis by publications, researchers, and others has consistently found that lower income groups are usually the worst affected. For example, the average heatwave exposure was 40% higher in the world’s poorest quarter than in its wealthiest quarter.


Women suffer from heatstroke more

Lastly, Polly also collected data on heatstroke engagement and gender.

Polly found that 72% of women reported suffering from heatstroke, while only 28% of men engaged on the topic. This aligns with the fact that women are physiologically more vulnerable to heatstroke than men. However, the US Environmental Protection Agency (EPA) reported that between  2001 and 2010, men were hospitalized for heat-related illnesses more than twice as often as women, and they are at higher risk as they tend to work in labor-intensive outdoor occupations such as construction.

Heatstroke affects millions of workers around the world every year. With the ongoing effects of climate change, it’s vital that companies empower their workers by educating them on how to avoid this dangerous heat illness.


About the data

The data was sourced from Polly, who created independent samples of 353,181 people from X, Reddit and TikTok globally, over a year, up until 8 April 2024. Responses were collected and analyzed to produce outcomes within a 90% confidence interval and 5% margin of error. Engagement estimated how many people in the location were participating. 

Demographics were determined using many features, including name, location and self-disclosed description. Privacy was preserved using k-anonymity and differential privacy. Results are based on what people describe online — questions were not posed to the people in the sample.

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