Core Viewpoint - An international study led by the Spanish National Research Council indicates that nighttime high temperatures may lead to an increase in global mortality rates, highlighting a significant health risk associated with this phenomenon [1] Group 1: Research Findings - The study analyzed over 14 million death records from 178 cities across 44 countries between 1990 and 2018, using hourly temperature data and statistical models to assess the relationship between nighttime high temperatures and mortality [1] - Nighttime high temperatures are positively correlated with increased mortality rates in all regions except Northern Europe, indicating that nighttime heat itself is a health risk factor [1] - Nighttime high temperatures hinder the body's recovery from daytime heat stress, affect sleep quality, and may exacerbate cardiovascular, respiratory, and neurological diseases [1] Group 2: Impact on Vulnerable Populations - Urban areas with strong heat island effects, such as Mediterranean cities like Barcelona and Valencia, experience higher frequencies of nighttime high temperatures, posing greater risks to vulnerable groups [1] - The most affected populations include the elderly, individuals with chronic illnesses, and residents in poorly ventilated or air-conditioned environments [1] Group 3: Recommendations - Researchers advocate for the inclusion of nighttime high temperatures in early warning systems, the development of urban climate shelters, and the increase of green spaces to mitigate health risks [1] - Ensuring adequate cooling conditions in homes, hospitals, and nursing homes is also recommended to protect vulnerable populations from the adverse effects of nighttime heat [1]

Group 1 - The phenomenon of "nighttime high temperatures" is caused by cloud cover that traps heat, preventing nighttime cooling [1][3] - Human activities, such as urbanization and transportation, contribute to higher nighttime temperatures due to heat retention in concrete and asphalt [3][4] - Global climate change factors, including increased greenhouse gases and water vapor, exacerbate nighttime warming [3][4] Group 2 - Nighttime high temperatures pose health risks, particularly for vulnerable populations such as the elderly, who have a reduced ability to regulate body temperature [4][6] - Recommendations for coping with nighttime high temperatures include improving air circulation indoors, staying hydrated, and being cautious about outdoor activities [4][6] - Special attention is needed for elderly individuals with heart conditions, as they may require careful management of fluid intake to avoid exacerbating health issues [6]

当夜幕降临，阳光辐射"断供"，地表大气会逐渐降温，但降温的程度取决于大气状况，不同的大气条 件，使累积在地表的热量释放速度出现差异。这是影响大气夜间温度的重要因素。 人类活动也是"夜间高温"的原因之一。许小峰说，城市建筑密集、植被较少，密集的混凝土、沥青道 路、砖石建筑等材料就像巨大的"储热池"，不仅增加了白天的热量储存，还增强了夜间的长波热量释 放。夜间交通、空调散热等人类活动持续产热，使得城市夜间温度明显高于郊区，暖夜更频繁。 此外，引发全球气候变化的因素同样会加剧夜间增温，大气中的温室气体、水汽增多，也不利于夜间地 表散热。 新华社北京7月30日电（记者侠克、田晨旭、李佳巍）高温高湿的"蒸煮"下，许多人发现：明明太阳已 经落山为何体感却更热？夜晚不应该更凉快吗？ "如果白天辐射很强，夜晚又遇云量增多的情况，云层就会像'被子'一样阻挡地面散热，导致热量滞 留，夜间降温缓慢，从而产生'夜间高温'。"中国气象服务协会会长许小峰说。 这是7月11日拍摄的位于天津五大道文化旅游区的"民园1920街区"一景（无人机照片）。新华社记者 赵 子硕 摄 许小峰介绍，白天的炎炎烈日以短波辐射的方式穿透大气，将热量传递至地表 ...