Chitosan nanoparticles (CNPs) have been reported to have a multidirectional role in agriculture, particularly increasing the resistance of plants to a variety of stress conditions. This chapter focuses on the behavior, stability, and efficacy of CNPs at both high and low temperatures, which significantly affect physicochemical properties as well as biological activities of CNPs. It looks into the impact of temperature variation on structural stability, kinetics of release, and interaction of CNPs with plant tissues. The chapter also delves into how CNPs help plants combat heat and cold stress by modulating physiological processes, enhancing antioxidant defense systems, and inducing gene expression related to stress. The behavior of CNPs to severe temperatures is important for optimizing their use in different agro-climate zones and to ensure the consistency of the effectiveness of stress management practices. Such insights could inspire the development of stable, climate-resilient nanoparticle compositions for sustainable agriculture.