A heated car seat may feel warm and toasty on a cold night, but it may also decrease a man's chances of becoming a father, according to a study published in the August issue of the journal Fertility and Sterility.

Andreas Jung, of the University of Giessen in Germany, and colleagues put a portable data recorder connected to two temperature sensors on the scrotums of 30 healthy men and measured sperm count and mobility at various times and seat temperatures.

Study authors said male fertility is at its peak when the core body temperature is below 99 degrees Fahrenheit. Volunteers agreed to twice sit at randomized times for 90 minutes on either heated or unheated car seats.

Researchers found that after just one hour of sitting on a heated car seat, the average scrotal temperature increased to 99.5 degrees and one volunteer's temperature reached 103 degrees.

The study’s authors concluded that frequent use of heated car seats may damage sperm production and could impact male fertility.

Click here to read more on this study published in Fertility and Sterility.