The fertility and reproductive efficiency of both male and female animals is very sensitive to climatic disturbances, particularly hyperthermia. The most evident consequences of heat stress are decreased quantity and quality of sperm production in males and compromised fertility in females. In this chapter, the effects of climate change on male and female reproduction have been separately and thoroughly elaborated. The effect of heat stress on embryo and fetal development has also been described. In the end, various approaches for mitigating the effects of heat stress on animals have been brought to light.