Ergonomics and Aerosol Technology, Department of Design Sciences, Lund University, 221 00 Lund, Sweden.
Int J Environ Res Public Health. 2019 Feb 15;16(4):560. doi: 10.3390/ijerph16040560.
Climate change increases the risks of heat stress, especially in urban areas where urban heat islands can develop. This literature review aims to describe how severe heat can occur and be identified in urban indoor environments, and what actions can be taken on the local scale. There is a connection between the outdoor and the indoor climate in buildings without air conditioning, but the pathways leading to the development of severe heat levels indoors are complex. These depend, for example, on the type of building, window placement, the residential area's thermal outdoor conditions, and the residents' influence and behavior. This review shows that only few studies have focused on the thermal environment indoors during heat waves, despite the fact that people commonly spend most of their time indoors and are likely to experience increased heat stress indoors in the future. Among reviewed studies, it was found that the indoor temperature can reach levels 50% higher in °C than the outdoor temperature, which highlights the importance of assessment and remediation of heat indoors. Further, most Heat-Health Warning Systems (HHWS) are based on the outdoor climate only, which can lead to a misleading interpretation of the health effects and associated solutions. In order to identify severe heat, six factors need to be taken into account, including air temperature, heat radiation, humidity, and air movement as well as the physical activity and the clothes worn by the individual. Heat stress can be identified using a heat index that includes these six factors. This paper presents some examples of practical and easy to use heat indices that are relevant for indoor environments as well as models that can be applied in indoor environments at the city level. However, existing indexes are developed for healthy workers and do not account for vulnerable groups, different uses, and daily variations. As a result, this paper highlights the need for the development of a heat index or the adjustment of current thresholds to apply specifically to indoor environments, its different uses, and vulnerable groups. There are several actions that can be taken to reduce heat indoors and thus improve the health and well-being of the population in urban areas. Examples of effective measures to reduce heat stress indoors include the use of shading devices such as blinds and vegetation as well as personal cooling techniques such as the use of fans and cooling vests. Additionally, the integration of innovative Phase Change Materials (PCM) into facades, roofs, floors, and windows can be a promising alternative once no negative health and environmental effects of PCM can be ensured.
气候变化增加了热应激的风险，尤其是在城市地区，那里可能会形成城市热岛。本文献综述旨在描述在城市室内环境中，严重高温是如何发生和识别的，以及在地方层面可以采取哪些措施。在没有空调的建筑物中，室外和室内气候之间存在联系，但导致室内严重高温发展的途径很复杂。这些途径取决于建筑物的类型、窗户位置、住宅区的室外热条件以及居民的影响和行为。本综述表明，尽管人们通常大部分时间都在室内，并且未来很可能在室内经历更多的热应激，但只有少数研究关注热浪期间室内的热环境。在审查的研究中，发现室内温度可能比室外温度高出 50%，这突出了评估和缓解室内热应激的重要性。此外，大多数热健康预警系统（HHWS）仅基于室外气候，这可能导致对健康影响和相关解决方案的误解。为了识别严重高温，需要考虑六个因素，包括空气温度、热辐射、湿度和空气流动以及个人的体力活动和穿着的衣服。可以使用包含这六个因素的热指数来识别热应激。本文介绍了一些适用于室内环境的实用且易于使用的热指数以及可应用于城市室内环境的模型的示例。然而，现有的指标是为健康工人制定的，没有考虑到弱势群体、不同用途和日常变化。因此，本文强调了需要开发专门适用于室内环境及其不同用途和弱势群体的热指数或调整现有阈值。有几种可以在室内环境中减少热量的措施，从而提高城市地区人口的健康和幸福感。减少室内热应激的有效措施包括使用遮阳设备（如百叶窗和植被）和个人冷却技术（如使用风扇和冷却背心）。此外，一旦能够确保相变材料（PCM）对健康和环境没有负面影响，将创新的 PCM 集成到外墙、屋顶、地板和窗户中可能是一种很有前途的替代方案。
