A new study challenges the belief that elderly people are most at risk from extreme heat. Research in Mexico shows that 75% of heat-related deaths occur among people under 35, with many in the 18-35 age group. This finding is surprising since younger adults are generally considered more resistant to heat.
“It’s a surprise. These are physiologically the most robust people in the population,” said study coauthor Jeffrey Shrader of the Center for Environmental Economics and Policy, an affiliate of Columbia University’s Climate School. “I would love to know why this is so.” The research appears this week in the journal Science Advances.
Researchers attribute it to factors like outdoor labor in farming and construction, indoor work in poorly ventilated factories, and strenuous sports. Young workers often face inflexible job conditions, increasing their exposure to heat-related risks like dehydration and heat stroke.
Infants and small children also face high vulnerability due to their limited ability to cool off and their weaker immune systems.
Heat-related deaths rising
The study, using Mexico’s detailed data on temperature and mortality from 1998 to 2019, found that the country experiences about 3,300 heat-related deaths annually. Interestingly, people aged 50-70 had the lowest heat-related death rates, while older adults died more frequently from moderate cold, especially in cooler, high-altitude areas.
While cold remains the leading cause of temperature-related deaths worldwide, heat-related mortality has been rising since 2000. With global warming, researchers predict that heat-related deaths will increase, especially among young adults in middle- and low-income countries where outdoor and manual labor is common.
The findings suggest significant implications for hot and developing regions, particularly in Africa and Asia, where populations are younger and work in agriculture is widespread. The research team plans to expand their studies to other countries, including the U.S. and Brazil, to confirm these trends.
The study, co-led by researchers from institutions including Columbia University, Stanford University, and UCLA, appears in Science Advances.