“…In humans, heat and vapor transfer are hindered by the clothing layers, the air enclosed within those layers, and the still air bound to the outermost layer (Havenith, 1999 ). Design modifications for enhancing heat loss through these layers include ventilation (both passive and active) (Bouskill, 1999 ; Lumley et al., 1991 ; McQuerry et al., 2018a , 2018b ; Reischl & Stransky, 1980 ), active cooling devices (Bach et al., 2019 ; Chicas et al., 2020 ; Tokizawa et al., 2020 ) and systems modularity which involves deploying certain layers of the ensemble for specific activities (McQuerry et al., 2020 ). For example, for firefighting protecting clothing, a single‐layer garment may be worn for search and rescue activities in lieu of the multi‐layer system (Jin et al., 2018 ).…”