The research team from Fudan University in China analyzed data from over 200 stroke centers throughout the nation, documenting the conditions of 82,000 adults admitted to hospitals with acute ischemic stroke (AIS) during periods of high temperatures from 2019 to 2021.

According to the British newspaper The Independent, the study examined the extent of the participants' exposure to high temperatures in the 24 hours preceding their stroke. The results revealed that exposure to temperatures reaching 33 degrees Celsius (91.4 degrees Fahrenheit) and above for only one hour could double the risk of an acute ischemic stroke compared to when the temperatures were at 12 degrees Celsius (53.6 degrees Fahrenheit) or lower.

The study also found that people with certain pre-existing health issues might be slightly more at risk, although the difference was not significant.

Acute ischemic stroke, which accounts for 70 percent of all reported strokes worldwide, occurs when blood flow to a part of the brain is blocked and can lead to disability or death.

While previous research has indicated a link between high temperatures and an increased risk of hospital admissions and death due to stroke, this study specifically focused on the impact of the duration of exposure to extreme heat on the risk of this condition.

Researchers state that the findings "underscore the need for governments and health bodies to take necessary measures to reduce people’s exposure to heat, particularly those who are at high risk of acute ischemic stroke."