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.

A Database of Static Thermal Insulation and Evaporative Resistance Values of Dutch Firefighter Clothing Items and Ensembles

“…However, most of the requirements are related to materials and material packages and not for the complete items or clothing ensembles. The current clothing systems in use are combined where possible and should ultimately lead to a fully integrated protective clothing system, of which digital support can be a part, for example, mobile applications, such as ClimApp [ 23 , 24 ] and decision aids [ 25 , 26 ]. In the future, possibly, the clothing system can be combined with the necessary sensors and smart solutions to acquire real-time input from the incident site to allow for the optimal selection of gear.…”

“…Clothing parameters for body regions can be measured, and the change due to walking and wind can be estimated [ 35 , 36 , 37 , 38 ]. Local values can be used in advanced physiological models for exposure evaluation [ 26 , 39 , 40 , 41 , 42 , 43 , 44 ], for occupational health and safety purposes, as a feedback for clothing manufacturers for improving their products, and/or for industries for selecting the clothing provided to their employees. In addition, some publications provide information on how to count for fit, garment size and/or airgaps [ 37 , 43 , 45 , 46 ].…”

“…Although, the studied clothing systems cover a wide variety of clothing configurations, it may be suspected that specialized clothing, e.g., the ones used by firefighters, may behave differently due to the protective layers and their combinations. Considering any future developments in clothing science and advanced support systems [ 23 , 25 , 26 ], and to select the best suited protection for any incident scenario in high stress situations quickly, more detailed information on thermal properties of clothing that is used by rescue workers is needed. As it is quite impossible to measure all possible clothing combinations used in the field, it is important to create an individual clothing items’ wardrobe database based on manikin measurements.…”

ClimApp—Integrating Personal Factors with Weather Forecasts for Individualised Warning and Guidance on Thermal Stress

“…Internationally established human thermal models and ISO standards and guidelines take the prime factors (environment, activity, clothing) into account for the assessment of thermal stress [ 10 , 11 , 12 , 13 , 14 , 15 ]. These may be used in existing national heat-health warning systems, but the thresholds used by weather warning systems have large variations between countries [ 5 ].…”

“…For instance, regional occupational heat-health forecasts are accessible via the HEAT-SHIELD platform, a website that combines weather forecasts with specific working conditions and provides a customised long-term heat-health risk assessment based on Wet Bulb Globe Temperature (WBGT) [ 4 ]. For national cold-health risk assessments, the windchill index is frequently used, and while other models exist (e.g., UTCI or CoWeDa), their potential is not yet fully used for national weather forecasts [ 10 , 13 , 16 ]. ClimApp takes the next step by downscaling the weather forecast to the individual level and providing personal cold and heat stress forecasts based on Global Positioning System (GPS) location, personal input and ISO thermal models.…”