Be Cool, Man

Myths and rumors relating to a man's fertility abound. The newest rumor is that hot tubs are sperm-killers. How should you rule: fact or rumor?

In this case, it seems there is some truth to the idea that hot tubs can jeopardize a man's fertility, at least for a temporary period of time. Think about it: men's testicles hang outside of his body rather than residing somewhere inside the body in a modest fashion. There's a good, scientific reason behind this chosen location for the testicles: the temperature of the body is too hot to sustain sperm. The sperm must be kept a bit cooler than body temperature or they will die.

Hot Shower

In general, exposing the testicles to a temporary heat source, such as a hot shower, may damage some sperm but will not have a long-term effect on male fertility. On the other hand, it is clear that the human body has been crafted to keep the male testicles cooler by several degrees than a man's body temperature. Consider the fact that studies have found sperm quality and sperm count to be highest during the coldest of the winter months and at an all-time low during the dog days of summer. It seems clear that a colder environment is the healthiest one for sperm.

So, when you hear people bring up the myths about male fertility and activities like wearing tight underwear, bicycling, taking a sweat in the sauna, or bathing in a hot tub, your friends are on to something. All of these activities are fine in moderation, but if you're trying to get pregnant, it's best to avoid such activities. This is even truer for couples having trouble conceiving due to a low sperm count. It is a definite fact that the heat that is generated during these activities has a negative impact on sperm.

While heat has more of an impact on sperm quality, rather than on the number of sperm produced, the damage inflicted by a hot tub may hurt sperm that are still months away from full maturation. The implications of one hot tub session on conception attempts months away tend to boggle the mind. On the other hand, the sperm count is restored to normal within one week after using a hot tub.

Sperm Damage

Other pertinent issues relating to sperm damage and heat sources include the level of the heat, how long the man is exposed to the hot water, and whether there might not be other activities and fertility factors to consider. Meantime, experts say that men who work in an environment with high temperatures may have poor-quality sperm. If a man does physical labor at an outdoor site and also indulges in hot-tubbing and bicycling, he is liable to manufacture poor-quality sperm.