Scientists are sounding the alarm as a new study reveals that heat-related deaths among young adults in Mexico are climbing due to climate change. Between 1998 and 2019, 75% of such fatalities involved individuals under 35, challenging the belief that heat primarily endangers the elderly.

Unseen Risks for the Young

The study, published in Science Advances, found that even moderate heat can be fatal for younger individuals. Researchers used “wet bulb” temperatures—a measure combining humidity and heat—to gauge human adaptability. Surprisingly, deaths occurred at lower wet bulb temperatures, around 75°F, a threshold previously thought safe for younger adults.

Why Are Young Adults Vulnerable?

Factors like outdoor physical activities, including work and sports, put younger people at higher risk. “It’s not just about physiology but also economic and social vulnerabilities,” explained coauthor Daniel Bressler from Columbia University.

The Future Looks Bleak

With climate change driving more heatwaves, the study predicts a 32% increase in heat-related deaths among young adults by 2100. “The rise in moderately warm days will far outpace extreme heat days,” noted Andrew Wilson, lead author and environmental social scientist at Stanford University.

This research highlights an urgent need for policies addressing both the physiological and socioeconomic impacts of rising temperatures on vulnerable populations.