Overheating in built environments during climate extreme heat events is a major concern to human health, particularly for people vulnerable to prolonged exposure to heat and humidity. However, currently available methods for assessing the risk of overheating lack robust procedures to evaluate the effects of overheating on the comfort and health of vulnerable occupants residing in the various different dwellings. This paper developed a general methodology to define and characterise overheating events and evaluate the risk to reduced comfort and undesirable health effects of building occupants exposed to extreme heat events. Criteria to declare overheating were developed based on heat-related health outcomes related to limits for body dehydration and core temperature of healthy average-age and older adults. The methodology was then applied to a case study of a residential building with typical local construction practice for cold climates and compared with existing methods for assessing risk from exposure to extreme heat events. The results showed that all the methods predicted that highly insulated and airtight buildings are more prone to overheating than older buildings that are less well insulated and airtight. However, only the proposed methodology described in this paper predicted that natural ventilation through opening windows significantly reduced the overheating risk to below the threshold value. Furthermore, multi criteria methods might be difficult to apply in practice in that it is not guaranteed to violate all the criteria to declare a building space is not overheated. The proposed methodology sets the groundwork for establishing a benchmark model from which different overheating metrics can be compared.

在气候极端高温事件期间，建筑环境中的过热是人类健康的主要问题，特别是对于那些容易长时间暴露在热和湿气中的人们。然而，目前用于评估过热风险的方法缺乏鲁棒的程序来评估过热对居住在各种不同住房中的脆弱乘员的舒适性和健康的影响。本文开发了一种通用的方法来定义和表征过热事件，并评估暴露于极端高温事件的建筑居民降低舒适感和不良健康影响的风险。宣布过热的标准是根据与健康相关的健康结果制定的，这些健康结果与健康的平均年龄和成年人的身体脱水限制和体温限制有关。然后将该方法应用于具有典型本地建筑实践的寒冷气候的住宅建筑的案例研究，并与现有的评估暴露于极端高温事件的风险的方法进行了比较。结果表明，所有方法都预测，与隔热性和气密性较差的老式建筑相比，高隔热性和气密性建筑更容易过热。但是，只有本文中描述的拟议方法可以预测通过打开窗户的自然通风将过热风险显着降低到阈值以下。此外，在实践中可能难以应用多准则方法，因为不能保证违反所有准则以声明建筑物空间未过热。