On the Effects of Clothing Area Factor and Vapour Resistance on the Evaluation of Cold Environments via IREQ Model

: The IREQ (Insulation REQuired) index is the only reliable and effective model for predicting and evaluating the protection given by a clothing ensemble in cold environments. Even with the growth of studies aimed at assessing the thermophysical characteristics of clothing, IREQ remained unaltered from Holmér's original formulation four decades prior. This paper focuses on the effect of the evaluation of the clothing area factor and the resultant vapour resistance on the assessment of cold environments via IREQ. Obtained results reveal meaningful variations in the duration limit exposure (up to 5 h), whereas IREQ values remain unchanged. Observed phenomena could be interesting when discussing the revision of the ISO 11079 standard, which prescribes using IREQ for the determination and interpretation of cold stress.