A new global study published in the medical journal Neurology has found that over half a million people died from strokes attributable to high and low temperatures in 2019 alone. The study, conducted by researchers from Xiangya Hospital Central South University in China, examined temperatures and stroke cases in 204 countries and territories.

The findings of the study indicate that the number of strokes caused by extreme temperatures has been on the rise worldwide since 1990. Surprisingly, the research revealed that men experienced a higher number of strokes related to hot and cold temperatures compared to women. Furthermore, strokes affected individuals of all age groups.

While the growing population and aging demographics contribute to an increase in stroke cases, the study emphasized that "nonoptimal temperatures" play a significant role. The data shows a substantial growth in stroke cases caused by extreme temperatures, with 2019 reporting a significantly larger number than in 1990. Interestingly, low temperatures were identified as the leading cause of strokes in 2019, despite the context of global warming. This can be attributed to the complex dynamics between warmer temperatures on land and disruptive effects on the polar vortex, resulting in cooler temperatures.

The study highlights that regions with high levels of poverty and fragile healthcare systems, particularly in Africa, bear a disproportionate burden of stroke deaths associated with extreme temperatures. Central Asia was also identified as requiring special attention due to the rapid increase in stroke cases caused by high temperatures.

With the planet warming at an alarming rate, the study warns of a sharp increase in the burden of strokes related to high temperatures. Last year, 2019, ranked as the warmest year since global temperature recordings began in 1850, and this trend is expected to continue, with March 2021 already marking the record as the hottest March on record.

Dr. Mary Rice, an associate professor at Harvard Medical School, has commended the study's comprehensive global approach, noting that the health issue of stroke deaths from extreme temperatures has not received sufficient attention. Dr. Rice's recent study also found a link between climate change and an increasing number of immune-mediated diseases, emphasizing the urgent need for multilevel actions to reduce emissions and improve air quality.

Stroke is already a significant global health problem, ranking as the third leading cause of disability worldwide and a leading cause of death. The study did not specifically investigate the mechanisms underlying the connection between extreme temperatures and strokes, but previous research has indicated that excessive heat impairs the body's ability to regulate temperature, leading to increased blood clotting and dehydration, which raise the risk of stroke. On the other hand, extreme cold temperatures can trigger vasoconstriction and spike blood pressure.

Neurologist Dr. Ali Saad, affiliated with the Climate and Health Program at the University of Colorado, stresses the importance of educating stroke patients about the dangers of extreme temperatures and incorporating weather alerts into their daily routines to prevent overheating. Dr. Saad hopes that this study will draw the attention of global leaders and influence public policies addressing climate change mitigation.

As extreme temperatures continue to pose a significant risk factor for strokes, this study serves as a clarion call for urgent global action. Failure to address this issue could lead to a substantial increase in the burden of strokes and other climate-related health problems in the near future.