Study Warns Extreme Heat Limits Daily Life for One-Third of World Population

A new study published in Environmental Research: Health warns that one-third of the world's population now lives in areas where extreme heat severely limits daily activities.

The research, led by Luke Parsons of The Nature Conservancy, analyzed 70 years of temperature, humidity and population data. It found that adults aged 65 and older face about 900 hours a year of heat conditions restricting safe outdoor activity, up from 600 hours in 1950.

The worst effects are concentrated in South Asia, Southwest Asia and parts of West Africa, including countries such as Afghanistan, Pakistan, India, Bangladesh, Bahrain, Qatar and Iraq. Vulnerable groups like the elderly and outdoor workers are most affected.

Luke Parsons stated that hundreds of millions of people can no longer safely carry out normal outdoor activities. He called for investments in heat protections and reductions in fossil fuel use to address the growing threat.

The study highlights how rising temperatures and humidity are making heat more dangerous, even for populations that have adapted to hot climates over generations.