Because of their immobility, plants are particularly exposed to environmental changes. The current climate of global warming threatens crop yields and there is an urgent need to better understand the impact of temperature changes on plant biology. Thermal stress particularly compromises male fertility and leads to a change in the expression of thousands of genes. However, the molecular actors of these phenomena are still poorly known. Using the Arabidopsis thaliana model plant and a direct genetics approach, the first phase of the Celcius project will identify the key genes needed for the plant’s transcriptional response during thermal stress. The second part of the project aims to generate plants with increased fertility under conditions of high ambient temperature, and/or increased resistance to transient thermal stress. Focusing on these two aspects, the Celcius project should thus contribute to the establishment of crops more suited to global warming by strengthening the foundation of necessary basic knowledge and providing concrete avenues for medium-term research.