一项针对 1950 年至 2024 年热度与湿度纪录的新同侪审查研究发现，全球因极端高温而不适合进行日常活动的时数已较 1950 年增加一倍。研究估计，65 岁及以上族群平均每年约有 1 个月无法安全地散步遛狗、清扫门廊或完成其他轻度任务；18 至 40 岁成人也因气候变迁驱动的高温，每年损失约 50 小时。整体而言，全球超过三分之一人口居住在高温已严重影响日常生活的地区。

研究使用联合国人类发展指数作为脆弱性代理指标，并以不同年龄层的生理热影响模型，判定人在阴影户外条件下何时已热到无法从事日常任务。Qatar 的高龄者如今约有一年三分之一时间面临例行活动风险；该国 18 至 40 岁族群每年也必须减少超过 800 小时日常活动，约占全年时间的 10%。在美国，高龄者可安全投入正常活动的时间减少了 270 小时，且美国南部每年对高龄者构成数百小时的宜居性限制。

自 1995 年以来，欧洲、南美洲南部、澳洲南部，以及亚洲与非洲部分地区的日常生活限制增幅最大。Jennifer Vanos 指出，长时间暴露于高温下，即使只是餐饮业工作者这类低强度步行，也可能变得危险。研究同时强调不平等性：Qatar 与阿拉伯联合大公国等富裕国家的居民或可依靠空调避暑，但其建筑等户外工作高度仰赖移工。该论文把这些结果置于 2024 年全球均温创新高、且年度升温首次超过 1.5 摄氏度（原文 1.5C）的背景下。

A new peer-reviewed study of heat and humidity records from 1950 to 2024 finds that the number of hours when extreme heat makes everyday activity unsafe has doubled globally since 1950. It estimates that adults aged 65 and older now face about one month each year when it is too hot to safely walk a dog, sweep a porch, or do other light tasks, while adults aged 18 to 40 lose about 50 hours a year to climate-driven heat. Overall, more than one-third of the world population lives in regions where heat now severely disrupts daily life.

Using the United Nations Human Development Index as a vulnerability proxy and a physiological heat model for different age groups, the researchers identified when shaded outdoor conditions become too hot for routine tasks. In Qatar, older adults now face risky heat for routine activity during about one-third of the year, while people aged 18 to 40 must cut back daily tasks for more than 800 hours annually, or about 10% of their time. In the US, older adults have lost 270 hours available for normal activity, and the southern US now sees many hundreds of hours of livability limits for seniors each year.

Since 1995, the largest increases in daily-life restrictions have occurred in Europe, southern South America, southern Australia, and parts of Asia and Africa. Jennifer Vanos said the findings show that prolonged heat exposure can endanger even low-exertion workers such as restaurant staff who spend long periods walking. The study also highlights inequality: residents of wealthy states such as Qatar and the United Arab Emirates may rely on air conditioning, but those economies depend heavily on migrant labor in outdoor sectors such as construction. The paper places these results against 2024, when global temperatures reached a record high and annual warming exceeded 1.5 degrees Celsius (originally 1.5C) for the first time.