Older Adults Face Dangerous Heat Risks at Lower Temperatures, New Study Finds
New Delhi, August 20, 2026: Older adults could face serious health risks from extreme heat at lower temperatures than previously estimated, according to a new study published in The Lancet Planetary Health.
The study found that if global warming reaches 3°C above pre-industrial levels, India, China, Pakistan and Bangladesh could together account for around 1.48 billion people exposed to dangerous heat, representing 72.6% of the estimated 2.03 billion people exposed worldwide.
South Asia and the Persian Gulf are projected to be among the regions most affected. At 3°C or more of warming, older adults in these regions could experience dangerous heat conditions during both daytime and nighttime for around three consecutive months.
Countries such as India, Pakistan, Bangladesh, Myanmar and Niger are expected to face particularly serious challenges because of the combination of high heat exposure, poverty and limited access to cooling facilities.
Why Older People Face Greater Heat Risks
Older adults are more vulnerable to extreme heat because the body's ability to regulate temperature declines with age. They tend to sweat less, their blood vessels respond more slowly and their hearts face greater strain in hot and humid conditions.
Researchers said previous studies largely relied on heat-tolerance data from healthy younger adults. As a result, earlier estimates may have underestimated the number of older adults at risk by at least two times.
The study examined heat tolerance across three age groups — adults aged 15-39, those aged 40-59 and people aged 60 and above.
Researchers then mapped areas where heat could become dangerous for each age group under warming scenarios ranging from 1°C to 4°C above pre-industrial levels.
The findings showed that accounting for age-related differences substantially increased both the estimated scale and geographical spread of heat risks.
The researchers said intolerable heat could affect more people, cover larger areas and persist for longer periods than previously recognised.
