A major challenge of mobile information technology use in time-critical work settings is to balance the temporal impact on the work practice caused by the technology. This paper presents results from an investigation of the tension between information technology use and temporal aspects in the timecritical work of emergency response. This paper contributes to previous research on the inter-related relationship between the temporal aspects of the work practice and the use of information technology. Results from a study based on participatory analysis indicate how technology can be designed and introduced to comply with temporal aspects in a work practice characterised by rigid temporal structures.