Thermal comfort range of a military cold protection glove: database by thermophysiological simulation

Abstract

The thermal insulation properties of a military wet/cold protection glove of the German Bundeswehr were investigated using the thermophysiological simulation device CYBOR with a heated full-scale hand model. The aim of this study was the physiology related and more reliable estimation of a database for the thermal comfort range of the glove in terms of environmental limit temperatures and maximum safe wearing times (limit times). For that purpose the simulation device CYBOR is equipped with a control feature allowing the simulation of the physiological effect that the blood flow into the hands as the dominant heat source is reduced with decreasing skin temperature (vasoconstriction effect). In the simulation test, the criterion defining the thermal comfort range of the glove was the maintenance of a minimum hand phantom skin temperature of 15 degrees C. For various assumed metabolic rates between 50 and 175 W m(-2) and environmental temperatures down to -22 degrees C, the maximum safe wearing times within the thermal comfort range of the military glove were estimated between only 20 min and almost 1 h. The used simulation scenario for the prediction of environmental limit temperatures, however, tends to deliver too low values in correlation to the estimated limit times and needs further critical consideration. The estimated data concerning the thermal comfort range of the wet/cold protection glove of the German Bundeswehr leads to the recommendation for a use of this model in mild cold climatic regions. The presented thermophysiological simulation procedure for the evaluation of the cold protection properties of gloves in terms of maximum safe wearing times within the thermal comfort range can be a useful tool to establish practical operating instructions for soldiers or civilians acting in cold environments.