Cracks often arise in mass concrete structures, due to the thermal stress and low tensile strength of early age concrete. To prevent the undesired thermal stress induced crack, controlling the temperature of concrete has been considered as an effective approach. In this paper, a temperature controlling measure evaluation system (TCMES) is proposed, which includes distributed fiber optic temperature monitoring, prediction of temperature and stress fields, and concrete crack risk evaluation. We first experimentally monitor the temperature evolution of the concrete using the distributed fiber optic temperature sensing. Then thermal parameters of in-situ concrete are retrieved by performing back-analysis. Subsequently, the concrete temperature field and thermal stress field can be predicted from the retrieved parameters and the experimental parameters of concrete. Under the concrete crack risk evaluation principles, temperature controlling measures for different stages are proposed. Our analysis indicates that the proposed system is an effective approach to prevent cracks of early age concrete.