Despite the active applications of thermal comfort indices for heat wave definitions, there is lack of evaluation for the impact of extended days of high temperature on health outcomes using many of the indices. This study compared the impact of heat waves on health outcomes among different heat wave definitions based on thermal comfort and air temperature. We compared heat waves in South Korea (cities and provinces) for the warm season for 2011–2014, using air temperature, heat index (HI), and web-bulb globe temperature (WBGT). Heat waves were defined as days with daily maximum values of each index at a specified threshold (literature-based, the 90th and 95th percentiles) or above. Distributed lag non-linear models and meta-analysis were used to estimate risk of mortality and hospitalization for all-causes, cardiovascular causes, respiratory causes and heat disorders during heat wave days compared to non-heat wave days. WBGT identified 1.15 times longer maximum heat wave duration for the study periods than air temperature when the thresholds were based on 90th and 95th percentiles. Over the study period, for heat waves defined by WBGT and HI, the Southwestern region showed the highest total number of heat wave days, whereas for air temperature the longest heat wave days were identified in the southeastern region. The highest and most significant impact of heat waves were found by WBGT for hospitalization from heat disorders (Relative risk = 2.959, 95% CI: 1.566–5.594). In sensitivity analyses using different structure of lags and temperature metrics (e.g., daily mean and minimum), the impacts of heat waves on most health outcomes substantially increased by using WBGT for heat wave definitions. As a result, WBGT and its thresholds can be used to relate heat waves and heat-related diseases to improve the prevention effectiveness of heat wave warnings and give informative health guidelines according to the range of WBGT thresholds.

尽管热舒适指数在热波定义中得到了积极应用，但仍缺乏使用许多指数来评估高温持续几天对健康结果的影响的评估。这项研究根据热舒适度和气温在不同的热浪定义中比较了热浪对健康结局的影响。我们使用空气温度，热指数（HI）和球形灯泡温度（WBGT）比较了2011-2014年韩国（城市和省）暖季的热浪。热浪被定义为每天中每个指标的最大值处于指定阈值（基于文学的第90和95个百分位数）或更高的天数。分布式滞后非线性模型和荟萃分析可用于估算因各种原因，心血管原因，与非热浪日相比，热浪日的呼吸系统原因和热障碍。当阈值基于第90和第95个百分位数时，WBGT确定的研究期间最大热浪持续时间是气温的1.15倍。在研究期内，对于由WBGT和HI定义的热浪，西南地区的热浪天总数最高，而对于气温最高的东南地区，热浪天数最长。WBGT发现因热病住院而产生的热波影响最大和最显着（相对风险= 2.959，95％CI：1.566–5.594）。在使用不同的滞后结构和温度指标（例如每日平均值和最小值）进行敏感性分析时，通过使用WBGT定义热波，热波对大多数健康结果的影响显着增加。因此，WBGT及其阈值可用于将热浪和与热相关的疾病联系起来，以提高热浪警告的预防效果，并根据WBGT阈值的范围提供有益的健康指导。