Heat stress assessment in severe hot work environments: integration of recovery time into the PHS index calculator

This paper presents an updated version of the Predicted Heat Strain (PHS) calculator based on UNI EN ISO 7933: 2023. The structural modification required a comprehensive revision of parameters, entailing the utilization of Java and Visual Studio for code alterations, followed by an exhaustive testing phase. Based on the input values, the redesigned version includes the calculation of Recovery Time (RT) expressed in minutes per hour, a facet absent in the antecedent version. Furthermore, the updated calculator streamlines the determination of acclimatization levels for individuals exposed to environmental conditions by proposing two user-friendly dropdown menus. Additionally, it incorporates an atmospheric pressure calculation contingent on altitude. The redesigned interface also facilitates the input of metabolic energy production and static clothing thermal insulation through a curated list of options, according to UNI EN ISO 8996:2022 and EN ISO 9920:2009 standards. Aside from streamlining the input of complex parameters, the redesign of the PHS calculator represents the pioneering tool for computing the duration of breaks required to safeguard workers exposed to hot environments