Progress on effects of heat stress on male reproductive function and its therapy

Spermatogenesis, the basis of male reproduction, is susceptible to internal and external environmental interferences that impair fertility. Heat-induced reproductive damage is one of the most important factors contributing to male infertility. The testes are located within the scrotum and need to be maintained 2-4 ℃ below the core body temperature, which is essential for normal spermatogenesis and sperm maturation. In the past 40 years, the global male sperm concentrations have consistently declined at an average annual rate of 1%-2%, accompanied by a sharp increase in the prevalence of sperm quality abnormalities such as oligozoospermia and azoospermia. In daily life, a variety of factors can elevate scrotal temperature, such as occupational exposure, lifestyle habits, and pathological conditions, resulting in varying degrees of reproductive injury. In this article, the effects of heat stress on male reproductive injury, the injury patterns associated with different hyperthermic modalities, as well as preventive and therapeutic treatments were described, aiming at a comprehensive and in-depth understanding of the mechanism underlying heat-induced reproductive injury, as well as providing theoretical guidance for the clinic prevention and therapy of male infertility.