The failure to respond to warnings can have fatal consequences, however, it is a common occurrence for even professional monitoring staff to overlook the warnings. This study developed a set of warning notification designs for remote emergency response and assessed their effectiveness by analyzing the performance and risk perception of monitoring staff through simulation experiments. Sixty participants of safety professionals (42 males and 18 females, Mean age = 28.71) participated in a within-subjects experiment, evaluating warnings with different design features and deciding whether to response. During the experiments, reaction time and task success rate were recorded for each warning task, and subjective scales were used to measure risk perception and response efficacy. The results indicate the positive effect of risk perception on enhancing performance, and demonstrate the impact of warning design features on shaping risk perception and response efficacy. Especially, the roles of warning icon and risk explicitness are emphasized. In addition, situation awareness and mental workload are proved to have positive impact on risk perception, while visual fatigue plays the opposite role. The findings demonstrate the effectiveness of enhancing risk perception and performance of safety monitors by controlling warning design features, contributing to the design of more effective emergency warning interface.