During professional situations, to cope with extreme environment, humans choose to involve collectively in action. Characteristics of these environments, with overturn time perception, high expectation demand, and concerns about uncertainty, are really difficult to take on by isolated people. In these extreme environments, High Reliability Organizations are able to bring under control and to lead action to mitigate risk and catastrophes. The organization must be resilient. In HRO, heedful interactions - contributing, representing and subordinating to action - are the core of successful actions. However, if collective and managerial processes are usually observed in research on the topic, very few enquiries focus on emotions, emotional labor and their impact on collective mind. We argue emotions are a part of communication. They give information about how people understand and feel environment and situation, that why they could be very useful to design collective actions. The management of the emotions is a part of the organizational resilience. Thanks to two case studies in different sectors (Intervention Police department, and Emergency Pediatrics Care units), this paper aims to explore/investigate the part of emotions and their effect on reliability of work.