Rising global temperatures could lead to 500,000 additional premature deaths per year by 2050 due to increased physical inactivity, a new study in The Lancet Global Health warns.
Researchers analyzed data from 156 countries between 2000 and 2022. Each month with average temperatures above 27.8°C correlated with a 1.5 percentage point rise in global inactivity-1.85 points in low- and middle-income nations.
Heat increases cardiovascular strain, dehydration risk, and perceived exertion, discouraging outdoor activity. Inactivity already causes 5% of adult deaths worldwide.
The hardest-hit regions will include Central America, the Caribbean, eastern sub-Saharan Africa, and equatorial Southeast Asia, where inactivity may rise over four percentage points per hot month.
Women and adolescents are especially vulnerable due to limited access to climate-controlled recreational spaces.
Cities must adapt through shade networks, reflective surfaces, and sheltered public areas to protect health and labor productivity.
Separate research confirms that becoming active reduces mortality risk by 22%. Walking 7,000 steps daily lowers risks of dementia, heart disease, and cancer significantly.