In the early 1970s, there was an initial effort to quantify the conditions under which firefighters are expected to perform. Harvey Utech led this endeavor by defining three levels of thermal exposure—routine, ordinary, and emergency—which were characterized by combining a range of air temperatures and radiative heat fluxes. In the last half-century, there has been a concerted scientific effort to further understand the conditions to which firefighters are exposed during structural firefighting. Research has been conducted on the resiliency of turnout gear and facepiece lenses, the thermal conditions observed during a structure fire, and the impact of firefighter tactics such as ventilation and suppression. The authors synthesize the results from these research areas to update the original thermal classifications to six categories of exposure—routine, Ordinary I, Ordinary II, Emergency I, Emergency II, and Emergency III—which are more representative of the operating environment and protective equipment thresholds that firefighters should be aware of during firefighting operations and tactical decision-making.

中文翻译：

---

提高结构消防员的热暴露等级

20 世纪 70 年代初，人们开始尝试量化消防员的工作条件。Harvey Utech 领导了这项工作，定义了三个热暴露级别（常规、普通和紧急），其特征是结合了一系列气温和辐射热通量。在过去的半个世纪中，人们进行了协调一致的科学努力，以进一步了解消防员在结构消防过程中所面临的条件。研究人员对消防装备和面罩镜片的弹性、结构火灾期间观察到的热状况以及通风和灭火等消防员策略的影响进行了研究。作者综合了这些研究领域的结果，将原来的热分类更新为六种暴露类别：常规、普通I、普通II、紧急I、紧急II和紧急III，这些类别更能代表操作环境和防护设备消防员在消防行动和战术决策过程中应了解的阈值。