Plant growth and productivity are severely affected by various environmental factors. These abiotic stressors are the major challenges to agricultural productivity and food security. Heat and cold stress are key abiotic stresses that limit crop production globally. With the ever-increasing global population, crop production is increasingly impacted by abiotic stress conditions, which trigger physiological and biochemical changes in plants, particularly in response to extreme temperatures such as cold and heat. Heat stress in particular arising as a result of industrialization and climate change has become a major threat to plant growth and productivity. It affects vital processes in plants including photosynthesis, germination, water retention as well as membrane stability, thereby reducing growth and yield of crops. Extremely low temperature is also known to halt plant growth and productivity by causing mechanical injury as a result of ice crystallization. To achieve sustainable agriculture under a dynamic climate, novel technologies, such as nanotechnology are becoming popular. Application of nanomaterials to plants under extreme temperatures especially at low concentrations, alters the physiological and biochemical parameters of the plant thereby improving growth and yield. This chapter emphasizes the roles of different engineered nanomaterials in overcoming high temperatures as well as cold stress in plants.