A digital tool for prevention and management of cold weather injuries-Cold Weather Ensemble Decision Aid (CoWEDA)

Abstract

This paper describes a Cold Weather Ensemble Decision Aid (CoWEDA) that provides guidance for cold weather injury prevention, mission planning, and clothing selection. CoWEDA incorporates current science from the disciplines of physiology, meteorology, clothing, and computer modeling. The thermal performance of a cold weather ensemble is defined by endurance times, which are the time intervals from initial exposure until the safety limits are reached. These safety limits correspond to conservative temperature thresholds that provide a warning of the approaching onset of frostbite and/or hypothermia. A validated six-cylinder thermoregulatory model is used to predict human thermal responses to cold while wearing different ensembles. The performance metrics, model, and a database of clothing properties were integrated into a user-friendly software application. CoWEDA is the first tool that allows users to build their own ensembles from the clothing menu (i.e., jackets, footwear, and accessories) for each body region (i.e., head, torso, lower body, hands, feet) and view their selections in the context of physiological strain and the operational consequences. Comparison of predicted values to skin and core temperatures, measured during 17 cold exposures ranging from 0 to -40°C, indicated that the accuracy of CoWEDA prediction is acceptable, and most predictions are within measured mean ± SD. CoWEDA predicts the risk of frostbite and hypothermia and ensures that a selected clothing ensemble is appropriate for expected weather conditions and activities. CoWEDA represents a significant enhancement of required clothing insulation (IREQ, ISO 11079) and wind chill index-based guidance for cold weather safety and survival.

Keywords: Clothing; Frostbite; Hypothermia; Manikin; Thermoregulation model.

Fig. 1

Cold Weather Ensemble Decision Aid flowchart

Fig. 2

Schematic of the six cylinder thermoregulatory model (SCTM)

Fig. 3

Cold Weather Ensemble Decision Aid (CoWEDA)

Fig. 4

Selected clothing for the region, e.g., upper body

Fig. 5

Menu of clothing options for each body region, e.g., upper body

Fig. 6

Activity panel pull down menu

Fig. 7

Cold weather ensemble Decision Aid For Subject Matter Expert (CoWEDA-SME)

Fig. 8

Comparison of measured and CoWEDA-predicted finger temperatures at the end of rest and exercise at 0, −20, −30, and −40°C wearing Extended Cold Weather Clothing System (ECWCS) and different gloves and boots

Fig. 9

Comparison of measured and CoWEDA-predicted mean skin temperatures at the end of rest and exercise at 0, −20, −30, and −40°C wearing Extended Cold Weather Clothing System (ECWCS) and different gloves and boots

Fig. 10

Comparison of measured and CoWEDA-predicted core temperatures at the end of rest and exercise at 0, −20, −30, and −40°C wearing Extended Cold Weather Clothing System (ECWCS) and different gloves and boots

Fig. 11

Comparison of measured and CoWEDA-predicted finger endurance times during rest at −20, −30, and −40°C wearing three different gloves and Extended Cold Weather Clothing System (ECWCS) and different gloves and boots