Assessment of risk considering both the probability of occurrence of a natural phenomenon and its consequences on the elements at risk is an essential step before the design of adequate risk reduction strategies in local, regional or national level. Within the EU-funded project SEERISK “Joint disaster management risk assessment and preparedness for the Danube macro-region”, a common methodology for risk assessment and mapping for climate change-related hazards has been developed. Vulnerability assessment is a large part of the risk assessment procedure, and it requires a considerable amount of detailed data. The methodology for risk assessment presented here is in line with the EC Guidelines for Risk Assessment and Mapping, and it provides alternatives in order to tackle the problem of varying data quality and quantity necessary for the analysis of hazard and vulnerability. In the present study, the methodology is adapted for heat waves and is applied in the city of Arad, Romania. Based on data regarding surface temperatures and emergency services interventions from past events during the daytime and the night-time, two hazard and two impact maps were developed, respectively, as well as a risk matrix for the night- and the daytime. A heat wave risk map was then developed that can be used by the emergency planners and services in order to prioritise their actions and focus on the hotspots as far as potential victims are concerned. The results of the case study apart from providing a tool for decision-makers and emergency planers also demonstrate the applicability of the common risk assessment methodology developed as being a profound theoretical basis for distinct risk-mapping exercises.