According to recent estimates, about 30% of the world population is currently exposed to particularly critical hot conditions for health for at least 20 days a year and this percentage is projected to increase in the coming years even if greenhouse gas emissions will tend to decrease. Workers, especially those who spend most of their activities outdoors, primarily in the agricultural and construction sectors, are among the most exposed to the effects of heat and in general to all atmospheric phenomena. The aim of the project is to deepen, especially through the INAIL injury database, the knowledge on the effect of environmental thermal stress conditions on workers (in particular heat), with specific attention to the estimation of the social costs of injuries at work. Organizational solutions and useful operational procedures in different occupational fields (or tasks), currently not yet available, will also be proposed through the organization of ad hoc case studies in selected companies in the areas of central Italy, a survey on the perception of risk linked to exposure to extreme temperatures will carried out too. An integrated weather-climatic and epidemiological heat health warning system, specific for the occupational sector, will be developed. The heat health warning system will consist of a web forecasting platform and a web app that will provide personalized forecasts based on the individual characteristics of workers and those of the work environment (work in the sun or in shade areas). The project products will be enhanced and made available by the Italian Physical Agents Platform (PAF) in order to provide concrete and operational support helpful not only for workers but also for all actors involved in the occupational prevention and protection process.