Okay, it’s not yet very hot at night despite the imminent arrival of summer. But in a world with a warming climate, it’s important to stay informed about the health implications.
“Elderly people and women are particularly exposed”
Over a period of 15 years, German researchers compiled nighttime temperature data in Augsburg (Germany) and the number of stroke cases recorded in the same city (more than 11,000 in total). Each year, the information was recorded during the warmer months, from May to October.
In the study published in the European Heart Journalscientists note a significant increase in risk of stroke (stroke) on days when warm nighttime temperatures were recorded. “Elderly people and women are particularly at risk, and it is especially strokes with mild symptoms that are diagnosed in clinics after hot nights,” the study reports. Overall, the risk of stroke has increased by 7% during nights described as “tropical”.
“Climate change is leading to an increase in nighttime temperatures”
THE “tropical nights” are defined using an index that measures the increase in temperatures above a certain threshold during the night. The threshold value is the temperature that is exceeded only during the hottest 5% of nights of the entire study period. In this study, this value is 14.6°C. If temperatures exceed this value during the night, it is called a tropical night.
The threshold value of 14.6°C appears low. But the increase in the number of strokes has increased over time, reflecting increasing temperatures. From 2006 to 2012, hot nights were linked to two additional strokes per year, while from 2013 to 2020, hot nights were associated with 33 additional cases per year. “It’s important because climate change is causing nighttime temperatures to rise much faster than daytime temperatures” said Alexandra Schneider, epidemiologist at the Helmholtz research center in Munich.
According to the researchers, several factors could explain these statistics, including a increased risk of dehydrationalready known to increase the likelihood of suffering a stroke.
