With one in three French adults already experiencing sleep disorders, rising temperatures could make matters worse. A comprehensive study by American researchers examined how environmental heat disrupts our natural sleep cycles. Our body temperature typically drops during sleep, but hot nights interfere with this process, making it harder to drift off. Analyzing data from 2002 to 2011, the team tracked 765,000 U.S. volunteers who reported their monthly poor sleep nights alongside local weather records. The findings were clear: higher temperatures correlated with significantly worse sleep quality.
Strikingly, a single degree increase in temperature led to three additional consecutive bad nights of sleep. Vulnerable groups include low-income individuals without access to air conditioning and those over 65, whose thermoregulation systems are less effective in heat. As global warming drives surface temperatures higher, projections suggest we could face up to six more poor sleep nights per month in the coming decades, including by 2050. These insights underscore the urgent health implications of climate change.
