Evaluating different working protocols in freezing chambers through a thermophysiological model

• A comparative study of five working protocols in freezing chambers. • Research sustained by field measurements. • Application of a thoroughly validated thermoregulation model. • Useful guidelines for working safely in cold environments are provided. • Two protocols were identified where workers’ thermal stress is nearly neutral. Working in freezing chambers involves alternating between very cold and warm environments, posing health and safety risks. Despite this, human thermophysiological responses in such conditions are under-assessed. This study evaluates cold stress in freezing chambers using field measurements and a thermophysiological model. Useful guidelines for improvement of protective clothing and of working periods in both environments are provided. The field study reveals that workers’ clothing often lacks sufficient insulation, risking whole-body cooling. The thermoregulation model is used to compare the current most often working conditions in freezing chambers with four other scenarios where more appropriate clothing or exposure times are employed. For instance, to maintain current exposure times, basic clothing insulation must increase from 0.24 to 0.35 m 2 K W -1 (from ≈ 1.6 to ≈ 2.3 clo). Alternatively, with existing clothing, cold exposure should be limited to 18 minutes and warm exposure must be at least 18 min.