The testicles are located outside of the body because they need to be two to three degrees cooler than the rest of the body for optimal sperm production. The body has many effective mechanisms to keep scrotal temperature at ideal levels, and it can handle most weather- and exercise-related heat changes. In general, for every one-degree increase in ambient temperature, the scrotal temperature increases by only about a tenth as much. Still, despite these effective mechanisms, the testicles can be exposed to amounts of heat that cause problems with fertility. How hot is too hot?
Low sperm count - Symptoms and causes - Mayo Clinic
Sperm cells are some of the most sensitive cells in the body. In fact, sperm are so sensitive to heat that the testicles hang outside of the body to preserve sperm from less than ideal body temperature. Sperm thrive in lower temperatures. This means that even small sources of heat can start to add up and damage your sperm count. While the effects of electromagnetic radiation on sperm cells is still being studied, the effects of the heat will quickly fry your sperm. Avoid this by keeping your cell phone in your back pants pocket, shirt pocket, or a separate bag. The warmth that makes hot water and saunas so relaxing also causes your testicles to be exposed to higher temperatures for an extended amount of time.
Up to 15 percent of couples are infertile. This means they aren't able to conceive a child, even though they've had frequent, unprotected sexual intercourse for a year or longer. In over a third of these couples, male infertility plays a role. Male infertility is due to low sperm production, abnormal sperm function or blockages that prevent the delivery of sperm.
But research shows otherwise. Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services.