In France, a prison construction plan has been launched under the presidency of Emmanuel Macron to improve the living conditions of prisoners. The aim of this plan is of course to provide decent living conditions for prisoners but also to promote their reintegration. It has been shown that an environment with poor thermal comfort due to excessive heat contributes to tension and violence, creating an environment that is unsuitable for successful reintegration.From feedback and studies, it is clear that summer thermal comfort is a major problem for living conditions in prison buildings. Therefore, it is urgent to find solutions to improve it. However, while the issue of thermal comfort has been widely studied in general, very little work has been done specifically on the prison environment. This is a major challenge as there are strong architectural constraints due to the fact that the design of prison buildings is primarily governed by security concerns. The measures usually developed to meet thermal comfort requirements (especially summer thermal comfort) are not always applicable to the prison environment.Thus, the aim of this thesis is to fill this gap by looking for a strategy that ensures good thermal comfort in prison buildings and, at the same time, is adapted to the constraints of a prison, economically affordable and, without significant adverse impact on the environment.To answer this question, this master thesis is based on the case study of the construction of the Marseille prison "Les Baumettes 3" which will start construction in 2022. Thus, this study consists of participating in the design of the prison building with regard to the thermal comfort of the prisoners in the prison cells. Using a numerical model, a strategy combining several passive solutions was simulated. Consequently, considering that the model is a sufficiently valid representation of the target, the results of the Marseille prison case suggest that it might be possible to provide decent living conditions for prisoners in terms of thermal comfort while respecting architectural, economic, and environmental constraints. The best strategy found is a combination of night-time mechanical ventilation, solar protections, a more efficient ahu (which uses adiabatic cooling), opening windows and the use of one approach of solar protections.As the results of this study are obtained in relation to the specific case the Marseille prison, called "Les Baumettes 3", these results cannot simply be duplicated to other cases. Thus, this study does not provide a generalizable solution but rather an approach for developing a solution. It provides guidelines for proposing a potentially effective strategy to address the issue of thermal comfort in prisons. In order to evaluate the strategy to be implemented for a specific prison building, it will be necessary to model this building with numerical simulations by implementing the solutions proposed and analyse the performances of these solutions to finally find the optimal strategy for the studied prison building. The objective is to optimise the strategy by finding the right compromise between each solution. This compromise is specific to each prison building project. In this way, the strategy will be perfectly adapted to the studied prison building and will be fully effective.