An emergency situation brings together individuals belonging to many different organizations, representing different organizational cultures including different usage of language. In this paper we propose that a common understanding is vital in managing emergency situations. Firstly, a simple emergency situation is presented where one of the causes for increased damage was simply due to a misunderstanding of language. Secondly, we propose a theoretical framework of how different organization cultures with their different uses of language can be integrated on the terminological level where the communication takes place. Thirdly, the presented example is reviewed. We show how situations such as the one in our example can be analyzed by means of the theoretical framework. Finally, we present the findings from a Delphi study conducted in Finland, which support the central thesis, i.e. the importance of a common understanding in emergency situations, and we propose using the Delphi method to find the critical domains in the flow of information between the different actors involved in disaster management.