The usability of ClimApp: A personalized thermal stress warning tool

ClimApp was developed to assist individuals in reducing the risk of exposure to thermal stress and to supply the user with individualized advice and recommendations. The tool integrates several human thermal models and heat indices with the local weather forecast and goes on to provide users with a prediction of their thermal stress based on their activity level, clothing level, and heat acclimatization input. Despite its innovative and interactive functionality, ClimApp's utility and ease of use should be considered to increase its usability. The usability of ClimApp was evaluated over two iterations: one usability lab test (n = 10) and one field test (n = 38) where first-time users completed tasks in ClimApp related to navigation, perceived ease of use, and perceived usefulness. Activity theory guided the analysis, and a directed qualitative content analysis was applied to evaluate the usability of ClimApp. The results suggest that there is room for improvement when assessing the universal design aspects, navigation, and information complexity, yet the participants perceived the tool as useful in the situated context.