Planning Military Drinking Water Needs: Development of a User-Friendly Smart Device Application

Potable water is essential to maintain health and sustain military operations, but carrying and transporting water is a major logistical burden. Planning for group drinking water needs is complex, requiring understanding of sweat losses on the basis of intensity of activity, clothing biophysical parameters, and environmental conditions. Use of existing prediction equations is limited to tabled doctrine (e.g., Technical Bulletin, Medical 507) or to individuals with extensive expertise in thermal biophysics. In the present project, we translated the latest updated equations into a user-friendly Android application (Soldier Water Estimation Tool, SWET) that provides estimated drinking water required from 5 simple inputs based upon a detailed multiparametric sensitivity analysis. Users select from multiple choice inputs for activity level, clothing, and cloud cover, and manually enter exact values for temperature and relative humidity. Total drinking water needs for a unit are estimated in the Mission Planner tool on the basis of mission duration and number of personnel. In preliminary user acceptability testing, responses were overall positive in terms of ease of use and military relevance. Use of SWET for water planning will minimize excessive load (water) carriage in training and mission settings, and will reduce the potential for dehydration and/or hyponatremia to impair Warfighter health and performance.