Hello Dr. Fulbright:
I have heard that heat (such as a hot bath or directly-applied streams of hot water in the shower) can reduce sperm counts (like a natural birth control). How much truth is there to that?
DJ

Dear DJ,
Exposure to heat impacts a man’s semen in primarily two ways:
1. It affects sperm motility. This is in part due to heat exposure damaging sperm as they mature in the epididymis.
2. It affects normal sperm production. (Men with fertility problems are often discouraged from submerging themselves in hot bodies of water).

Heat should not, however, be regarded as a form of birth control. Having sex in a hot environment, like a hot tub, does not prevent pregnancy of sexually transmitted infections.

Dr. Yvonne Kristín Fulbright is a sex educator, relationship expert, columnist and founder of Sexuality Source Inc. She is the author of several books including, “Touch Me There! A Hands-On Guide to Your Orgasmic Hot Spots.”