Global Heat Stress on the Rise as Europe, South Asia, Africa and Latin America Face Intensifying Heatwaves

A major international study published in Nature Climate Change has found that global heat stress has intensified sharply since the 1970s , with countries across Asia, Africa, Europe and the Americas now experiencing up to two additional months of dangerous heat conditions. The findings come amid severe ongoing heatwave alerts across Europe, including emergency red warnings in France and record-breaking temperatures across multiple countries.

The research highlights that nations such as Mexico, Kenya, Italy and Pakistan are experiencing expanding heat stress seasons, with regions previously unaffected now increasingly exposed. Scientists attribute the trend to rising global temperatures driven by fossil fuel emissions and worsening humidity-driven heat stress.

According to the study, heat stress days and tropical nights have increased significantly, with some regions seeing up to 50 additional high-risk days annually compared to the 1970s. Europe is among the fastest-warming regions, with France placing 54 departments under red alert , while temperatures above 40°C have disrupted transport, schools and public life. Reports also indicate fatalities linked to extreme heat, including drowning incidents as people attempt to cool off.

The study uses the Universal Thermal Climate Index to measure “feels-like” heat conditions, showing that humidity is amplifying health risks by reducing the body’s ability to cool through sweating. Researchers also note that nighttime temperatures are rising faster than daytime highs, leading to dangerous tropical nights where the body cannot recover.

Experts warn that one billion more people now experience extreme heat stress annually than in the 1970s, with exposure rising across Asia, Africa, Europe and the Americas , underscoring a widening global climate risk.