Dear Waterman,

No, having sex in a hot shower, a hot tub, or in any kind of watery environment does not protect against either pregnancy or sexually transmitted infections (STIs).

A man's external sexual organs consist of the penis and the scrotum. The scrotum, the pouch that contains a pair of testes, maintains the testes at a temperature approximately 5 degrees less than the rest of the body (about 93.6°F). This function is important to fertility because the process of sperm production is heat sensitive. In hot temperatures, the muscles in the scrotum relax, and the testes move away from the heat of the body. Conversely, in cold temperatures, the muscles of the scrotum contract so that the testes can maintain their 5-degree temperature difference. The increase in temperature caused by sitting in a hot tub can indeed interfere with normal sperm production, but not enough to be considered an effective form of birth control. Men with fertility problems are usually told to avoid hot tubs, saunas, and the like; for men with normal fertility, using a condom or another form of birth control is preferable to not using any protection at all.

Alice

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