Thermal Environment Laboratory, Faculty of Engineering, Lund University, Lund, Sweden.
Glob Health Action. 2010 Nov 29;3. doi: 10.3402/gha.v3i0.5719.
Presumed effects of global warming on occupational heat stress aggravate conditions in many parts of the world, in particular in developing countries. In order to assess and evaluate conditions, heat stress must be described and measured correctly.
Assessment of heat stress using internationally recognized methods.
Two such methods are wet bulb globe temperature (WBGT; ISO 7243) and predicted heat strain (PHS; ISO 7933). Both methods measure relevant climatic factors and provide recommendations for limit values in terms of time when heat stress becomes imminent. The WBGT as a heat stress index is empirical and widely recognized. It requires, however, special sensors for the climatic factors that can introduce significant measurement errors if prescriptions in ISO 7243 are not followed. The PHS (ISO 7933) is based on climatic factors that can easily be measured with traditional instruments. It evaluates the conditions for heat balance in a more rational way and it applies equally to all combinations of climates.
Analyzing similar climatic conditions with WBGT and PHS indicates that WBGT provides a more conservative assessment philosophy that allows much shorter working time than predicted with PHS.
PHS prediction of physiological strain appears to fit better with published data from warm countries. Both methods should be used and validated more extensively worldwide in order to give reliable and accurate information about the actual heat stress.
全球变暖对职业热应激的推测影响加剧了世界许多地区的情况，尤其是在发展中国家。为了评估和评估条件，必须正确描述和测量热应激。
使用国际认可的方法评估热应激。
有两种这样的方法，即湿球黑球温度（WBGT；ISO 7243）和预测热应变（PHS；ISO 7933）。这两种方法都测量相关的气候因素，并根据即将发生热应激的时间提供限值建议。WBGT 作为热应激指数是经验性的，被广泛认可。然而，它需要特殊的传感器来测量气候因素，如果不遵守 ISO 7243 的规定，可能会引入显著的测量误差。PHS（ISO 7933）基于可以用传统仪器轻松测量的气候因素。它以更合理的方式评估热平衡条件，并且适用于所有气候组合。
用 WBGT 和 PHS 分析类似的气候条件表明，WBGT 提供了一种更保守的评估理念，允许的工作时间比 PHS 预测的要短得多。
PHS 对生理应变的预测似乎更符合来自温暖国家的已发表数据。为了提供有关实际热应激的可靠和准确信息，这两种方法都应在全球范围内更广泛地使用和验证。
