[en] The ACPR (the French Prudential Supervision and Resolution Authority) together with the Banque de France (French Central Bank) conducted a climate stress testing pilot exercise from July 2020 to April 2021 to assess the exposure of banks and insurers climate risks. It mobilised 9 banking and 15 insurer groups, covering respectively 85% and 75% of their total balance sheet. This exercise is part of movement from European supervisors and regulators to assess the risks and challenges posed by climate change on financial stability: the Bank of England and the European Central Bank will conduct climate stress testing exercises on the basis of the same scenarios (provided by NGFS, the Network for Greening the Financial System); while the Basel Committee is advancing on its strategy to integrate climate related financial risks into banking prudential regulation. Despite current limitations due to the pioneering nature of this exercise, we welcome its realisation which has the merit of raising awareness on climate-related financial risk. As climate stress testing will become recurrent, banks and insurers will have to gain expertise in climate scenario modeling, understanding of climate risk transmission channels and rely on better forward-looking data and improved methodologies. This exercise involves stressing the balance sheets of French banks and insurers with a set of common hypotheses: a long time horizon (2050), the use of transition and physical risk scenarios broken down in sectors, and a dynamic balance sheet assumption (institutions can adapt their balance sheet over time). Participants were subject to three transition risk scenarios (all reaching 'net zero' emission), and one physical risk scenario, (the RCP8.5 from the IPCC, or a 'Business as Usual' scenario), based on a 30-year time frame. The exposure of French banks and insurers to transition risks is revealed as 'moderate', but our analysis shows that several elements indicate a potential downward bias, or an underestimation of transition risks. Physical risks lead to a significant increase in claim costs and insurance premiums. While these do not directly endanger insurers balance sheets, it will widen the insurance protection gap, with the insurability line being pushed further