The climate crisis poses a significant threat to both human existence and biodiversity. Its impacts on human health are already profound, particularly in vulnerable countries such as Bangladesh and Senegal. These regions have experienced temperatures rising at twice the global average, making them even more susceptible. Extreme temperatures (ET) affect health in various ways, with pregnant women and young children being the most vulnerable. There are significant concerns that the consequences of climate change could negate recent improvements in maternal and child mortality rates. While there is evidence from developed countries linking ET to increased risks, such as hypertensive disorders, pre-eclampsia, dehydration, and mental health disturbances, there is a conspicuous absence of such data from African and South-Asian regions. Both Bangladesh and Senegal face public health challenges posed by climate change and ET. HEAT-BaSe project aims to delve deeper into understanding these impacts and finding ways to reduce them. It aligns with the recent French global health strategy, emphasizing the urgency of public health intervention research. Key objectives include: 1. Tracking the evolution of spatial inequalities of ET and related diseases in Satkira, Bangladesh. 2. Understanding the inequalities and resilience mechanisms in the context of ET. 3. Setting up a micro-surveillance system for ET to measure and understand resilience. 4. Designing, implementing preventive physical and mental health interventions and evaluation of these intervention for mothers and children to counteract ET-related inequalities in both Bangladesh and Senegal. 5. Influencing local and national policies to address the impacts of ET. 6. Fostering international cooperation, sharing methodologies, and learning from interventions across regions. An inter-disciplinary approach underpins the project. The overarching goal is to devise and implement strategies that can mitigate the detrimental effects of ET on vulnerable populations.