Can using heated car seats reduce fertility? A family member warned me not to use heated car seats, since they cause infertility and cancer in both men and women. I searched the internet for a source for his claims and I found this Telegraph article from 2008 claiming might reduce fertility in men: > Heated car seats could reduce male fertility, say scientists > > Men who use heated car seats could be unwittingly putting their fertility at risk, new research suggests. Is this a correct interpretation of their source? Has any other research been conducted that confirms or refutes this?

The Telegraph article may be correct.

There was a study that showed that sitting on a heated car seat increases scrotal temperatures by about 0.5°C. <

It is known that 'raised testicular temperature has a detrimental effect on mammalian spermatogenesis and the resultant spermatozoa' <

For optimal spermatogenesis to occur, testicular temperatures need to be maintained 2–4°C lower than core body temperature. <

So if somebody's scrotal temperature is an optimal 4°C below core then raising it by 0.5°C (by using a car seat warmer) probably won't affect fertility significantly. But since googled pictures of 'scrotal thermometer' do not inspire confidence in everyday use it is best to go along with a common sense advice to limit heated seat use to a minimum.