Thermoregulation of human hands in cold environments and its modeling approach: A comprehensive review

Cold environments pose significant risks to human health, well-being, and productivity, with hands being particularly vulnerable to cold stress and injuries. Mathematical models of hand thermoregulation have emerged as valuable tools for understanding and predicting hand performance and injuries, especially in extremely cold environments. While significant progress has been made in mathematical modeling, a systematic review of these models is currently lacking. This paper aims to fill this knowledge gap by conducting a comprehensive review of the existing literature on hand thermoregulation models in cold environments. It begins with an introduction to the unique thermophysical and thermophysiological characteristics of the hand. It then summarizes the historical evolution of hand thermoregulation models. The essential principles for developing hand-specific thermoregu-lation models are outlined, encompassing modeling of hand anatomy and geometry, thermophysiological re-sponses, and heat transfer between the hand and its surroundings. This review presents prediction methods for cold injuries and hand performance. The need for future advancements in hand thermoregulation modeling is emphasized. Specifically, achieving a more realistic representation of hand anatomy and geometry, as well as incorporating location-dependent thermophysical properties and physiological behaviors of the hand, are identified as crucial areas for improvement to enhance prediction accuracy. This review will contribute to a deeper understanding of hand thermoregulation mechanisms and their interaction with cold environments, as well as the development of more reliable and applicable models.