As heat waves grow longer and more intense, older adults face a particular danger that is easy to underestimate: the harm does not stop when the sun goes down. New research finds that cooling a home overnight may not be enough to protect older people from the physiological effects of repeated daytime overheating during a multi-day heat wave.
The study suggests that the body carries a kind of accumulated strain from consecutive hot days, and that a cool night cannot fully erase the damage already done. Older adults are especially vulnerable because their ability to regulate temperature declines with age, and many also live with conditions or take medications that interfere with cooling. The findings have direct implications for how communities respond to extreme heat. Advice to simply turn on the air conditioning at night may be insufficient; what may be needed is sustained protection throughout the day, along with checks on vulnerable neighbours. As climate change drives more frequent and severe heat waves, understanding these subtle risks becomes ever more urgent.
