A recent study published in *The Lancet* has highlighted a concerning oversight regarding the impact of extreme heat on individuals aged 60 and above. Researchers from Stanford University have found that the effects of rising temperatures on older adults are vastly underestimated, suggesting that as global temperatures continue to climb, a significant portion of this vulnerable demographic could face severe health risks due to extreme heat.
Alarming Projections for Older Adults
The study assessed heat tolerance across three age brackets: young adults (18–39 years), middle-aged adults (40–59 years), and older adults (60 years and above). It projects that if global temperatures rise by 1.5°C, approximately 22 per cent of the world’s older adult population will encounter “frequent and widespread exceedance of heat-compensability limits.” This term refers to the point at which the human body can no longer effectively cool itself in extreme heat.
According to NASA, the current average temperature on Earth sits at 2.14 degrees Fahrenheit (1.19°C) above pre-industrial levels, with 2024 being recorded as the warmest year to date at 2.30 degrees Fahrenheit (1.28°C). As the planet heats up, the study underscores the urgent need to comprehend where and when environmental conditions might surpass human heat tolerance.
Hotspots of Vulnerability
The report reveals that India has the highest number of individuals exposed to extreme heat, with an average of 648.4 million people facing at least 180 hours of “uncompensable heat stress” annually at 3°C warming. The urgency of the situation extends beyond India, encompassing nations such as Pakistan, Bangladesh, Myanmar, and Niger, all of which exceed both absolute and proportional exposure thresholds.
Alarmingly, an estimated 10 million older adults, representing 80 per cent of the senior population, are expected to experience 180 hours or more of heat limit exceedance each year. Moreover, older individuals residing in South Asia and the Persian Gulf may endure prolonged exposure to extreme heat—potentially lasting three consecutive months at temperatures exceeding 3°C.
Growing Elderly Population at Risk
The ageing global population adds another layer of concern. The number of people aged 60 and over is set to double from one billion in 2020 to 2.1 billion by 2050, making up 21 per cent of the world’s population. This demographic shift will place an increasing number of older adults at risk, particularly in low- and middle-income countries that are already grappling with emerging heat stress challenges.
The study contends that previously established projections, which primarily focused on younger adults, may have significantly downplayed the extent and urgency of heat-related risks facing older adults. As the climate crisis deepens, the health implications for this vulnerable group are becoming increasingly dire.
The Rising Toll of Heat-Related Mortality
The 2025 report from the Lancet Countdown on Health and Climate Change, in collaboration with the World Health Organization (WHO), reveals that heat-related mortality has surged by 23 per cent since the 1990s. Currently, heat-related deaths average 546,000 annually. In 2024 alone, individuals experienced an average of 16 days of dangerous heat that would not have occurred without climate change, with infants and older adults seeing up to 20 heatwave days each—a staggering fourfold increase over the past two decades.
In Canada, the population is projected to reach approximately 41.4 million by April 1, 2026, reflecting a slight decline from previous estimates. The implications of these demographic changes, alongside escalating heat risks, underscore the need for proactive measures to safeguard public health.
Why it Matters
The findings from this study serve as a clarion call to policymakers and health officials worldwide. As global temperatures continue to rise, the health risks faced by older adults must be prioritised in climate action strategies. With the elderly population growing and increasingly vulnerable to extreme heat, comprehensive planning and interventions are essential to mitigate the impending health crisis. Addressing these challenges head-on will be crucial in ensuring the safety and well-being of one of society’s most at-risk groups as we navigate the realities of a changing climate.
